> 4) Any single ISY can belong to no more than 3 accounts/subaccount
This is a limitation of the Admin Console, not portal. If using eisy-ui to approve/reject accounts, there is no limit.
The limit on Admin Console is higher than 3, probably 5 if memory serves well.
> 5) You can not delete a user (or account holder either) and add them as a user to a different (sub)account. You need to make a ticket with UD and ask them to delete the user email from the system if you want to move them to a different (sub)account. After they are deleted, you can invite them to be a user on a different (sub)account.
Actually you can delete a user, as long as the user is an account admin. If there is only one user left in an account, and he is not an account admin, then you are stuck.
If the user is in a subaccount of yours, then you can delete the user and the subaccout.