Avoiding heavy shaders like CRT is kinda of a requirement, but overall there's no way to port GMS 2 shaders yet (Working on that), so even if the Vita could handle the CRT shader perfectly, I don't have a way to port it at all.
Text is never a problem. The only game that gave me problems is Warlord, but it's due to a text parsing issue. It converts the newlines to an square and it doesn't, you know, break the line. I find this rather strange and I'm not really sure why it's happening at all.