bpwwer

You may have exceeded the number of API calls your plan allows for in a day.  The free plan is quite limited. Or you may have asked for more forecast data than what your plane allows.
It looks like they may have reduced the number of days of forecast data you can get with the free plan from 7 to 6.  The node server gets stuck if it's looking for 7 days but only sees 6.

Yes, you can run multiple copies of any node server.  So in theory, you can run two copies each linked to a different smart bridge.

Currently the only "feature" difference between PG3 and PG3x is that PG3x is getting remote access support.  We can't do remote access for PG3 which is one of the main reasons PG3x was developed.   There are internal changes in PG3x that make the node servers more secure but that's not something that is user visible.
There are no other plans for PG3x specific features other than those that are enabled because of the remote access framework.  An example is that there is a Ring node server that will piggyback on the remote access framework and thus, will only run on PG3x.
As mentioned above, Polisy is capable of running PG3x and there is a migration path available to switch.  We can migrate from PG3 -> PG3x but we don't have an easy way to migrate back so make sure you make backups of everything before attempting to migrate PG3 -> PG3x.

Disconnected means it was unable to connect to the local (or configured) IoX.  There are only a few different reasons it wouldn't be able to connect and viewing the log should reveal which.
1) the ISY software isn't running.  In this case you also would not be able to start the admin console.  The log would show a connection refused error.
2) The IP address is configured wrong. By default it's using the local address 127.0.0.1:8080 which is the local IoX.  If you didn't change the configuration, then this should be correct.  Again, you'll get a connection refused if it trying to connect at the wrong address.
3) The credentials are wrong. It starts with the default of admin/admin, but is supposed to update them if you log into PG3x with something different.  The log will show 401 (authentication) errors in this case.  You can update the credentials manually in PG3x via the ISYs -> Edit current ISY menu.

PG3x version 3.1.23 was extra chatty as we used that to do some initial testing for PG3x remote access.  That has been removed in the latest version 3.1.24 of PG3x.

3.1.18 hasn't been released to production yet so if 3.1.16 is working then no PG3 upgrade is needed at this time.

Looks like there's a bug in the latest PG3x release that's preventing it from removing node servers.

Some older node servers/older versions of node servers can't auto-update because PG3 doesn't have enough information to know what to update.  In those cases, selecting the correct install option / re-install to same slot should update the node server.

You're close.
Yes, you need to add a custom parameter with the "Port" "key" field and then the value will be the port that you configure in Meteobridge API URL.
If you configure the API URL as "http://10.0.0.56:8045", then you'd set "Port" to 8045
Note, that the IP address in the API URL is the Polisy's IP address.
Note2, notice I didn't use port 8080, port 8080 is already in use by the IoX running on the Polisy so you can't use that.  When you configured the API URL with that, Meteobridge was trying to send the data to the IoX which rejected it.
Note3, I believe the key name is case sensitive so "Port", not "port".

unmanaged, means that they are not being managed by PG3 but by something else. That's why you can't delete them.
In your case, I suspect they are being managed by a previous installation of PG3?  or PG2?  
You can delete them from the Admin Console.  Go to Node Servers -> Configure -> slot number for the node server slot you want to delete and click on the "Delete" button.  After a few minutes they should disappear from the PG3 dashboard.

Yes, there are bugs related to auto-updating node servers on PG3x. They'll be fixed in the next update.

Roku node server version 2.0.5 should fix the errors

@palaymanYes  polyglot.universal-devices.com lists all current node servers and clicking on the node server brings up the details including price(s).

I screwed up the packaging.  You'll have to re-install but it should work now.
Go to the node server store, select refresh store.  Then select the node server, click the install button and use the "Reinstall here?" button to re-install.

You're right. Fixed in version 2.0.8

Use the "install dev packages" option in the admin console configuration tab and then try again. 
If you don't have an install dev packages option, you'll need to upgrade packages first.

Looks like Emporia changed the API slightly.
I updated the node server and it should work now.  Version 1.0.23

The data reported by the node server is what the Ambient servers report.  There's no conversion happening in the node server.

Try logging out and then see if you can log back in.

I finally got around to trying it myself.  The problem is the node server is requiring a very old version of the interface module and that old module doesn't support PG3x MQTT.
@Javiin the requirements.txt you have udi_interface == 3.0.32.  Version 3.0.32 is a very old version of the file. The latest is 3.0.51.  You should probably use udi_interface => 3.0.51 and update the store entry version.
@garybixlerOnce the node server is updated to use the latest udi_interface, you'll need to do a re-install (note, not delete and install) for it to pick up the change.

No, it can't.  The admin console has full control over how the content is rendered. The node server (via PG3(x)) simply sends the value (numeric value).  
The only control the node server has is over values that are represented with text.  The node server creates the numeric value to text mapping that the admin console uses.
 

The node server is probably already running, just not connected to PG3.  
ps auxww | grep weatherstation.py  and see if it shows up in the list.  If so, then it needs to be killed before you can start it from PG3.   

No, beyond just that increasing the log level results in more log info.
If set to Critical, you'll probably see nothing, ever.  I'm not sure if there are any messages at that level.  If there are, it is very few.
error and warning are just as they say.  Error messages and/or warning messages only are output to the log.
info are messages that report what PG3 is doing.  This is the default and generally provides enough information to figure out what PG3 is doing at any given time.  
debug provides even more detail on what is happening.  It tends to be used for things that might be nice to see when debugging but generate so much log output that it can make the log harder to read.
db operations adds all the reads/writes to the PG3 database into the log.  This generates a huge amount of log info and is only going to be useful when trying to track what is being read or written from/to the database.
In general, there's no real reason to change from the default unless you're working with support and they request that you do so.

The error message means there's a browser running the UI that is not longer authorized to connect to PG3, but continues to try.
The connection between the UI running on the browser and PG3 is only good for about a week and and then it expires.  When it expires you need to log out and log back in to the UI (and maybe reload the page in the browser). 
I see this a lot because I'll sometimes have multiple tabs open to PG3 and forget about one.  That one will expire (or I'll restart PG3) and the forgotten tab will keep trying to communicate with PG3 and get rejected with that error.

Your current installation of Kasa is too old to support automatic updates.  The information needed for PG3 to determine what you purchased didn't exist when you did the initial install of Kasa.
You need to either upgrade PG3 to 3.1.16 which will then allow you to re-install from the purchase page or go through the node server store and re-install the node server that way.
In either case, you'll need to select the proper install option and re-install.  A re-install will keep all your current configuration and nodes so you won't lose anything by re-installing.