Well, you can put any kind of scripts into the wallet's code, but without a specific application (a user case), I don't see how I could add anything more.
So far gocoin supports the following output scripts:
* P2KH address (a regular bitcoin address)
* P2SH address (that's for multisig)
* NULL output describing the next one's encrypted constant (for stealth payments)
* NULL output with an arbitrary data (e.g. to attach text messages to transactions)
Adding other kind of output scripts is not really a challenge, but I need a specific application for it, before I can put it in.

As from the node's side.
Gocoin node (unlike bitcoin-qt) does not split transactions into "standard" and "non-standard".
As long as the fee per byte is sufficient (plus some other rules are met), it will get routed, despite of the content of a script.

EDIT:
Personally I think that dividing transaction into "standard" and "non-standard" has been a really stupid idea and I just cannot believe that instead of abandoning it they are just adjusting the rules of the standardness - that's crazy! It would be nice though to measure txs by how much CPU power they require to get verified - and then check the fee not only against the size, but also against the CPU required. But that seems like a too much advanced solution for the mainstream - it will take them at least 5 years to find out that this is an idea worth exploring