At the end of the 30-day trial I will lose access to whatever free games I played.

At the end of the 30-day trial what happens to the trophies I've gained in those free games?

They vanish.

All is for nought Euphoria

You keep the trophies, not the games

Cool. 

Thats the worst part of the Welcome Back program.

Sony offers you something that will last only 30 days unless you pay her more.

What kind of gift is that?

It is a tease, a small piece of pie. 

Wait wait wait wait wait, so those free games that you can get for PS + like Sonic 2, tower of something, and something tower defense will vanish once the free 30 days end??????

Yes. . . Playstation Plus works that way. 

1 dude said you keep them and another dude said you lose them...
Make up your mind people! :P I'd like to know this.

Trophies you keep, game you don't! :P