I second what the posters above have already said. Chainfire 3D will allow you to play those games for now, but with time these games will be updated to work with the 7.0 Plus. The same goes for the tablet apps.
To answer your second question, the 8.9, (since it is Tegra 2) can handle everything you have discussed in your post, and it is closest in size to the 7.0 Plus of all of the tablets you have mentioned. If you like the portability of the 7.0 Plus, a move to the Transformer or the Thrive, (especially the Thrive as it is so thick,) will feel a good deal less portable.
My advice, (for what it's worth) would be to get chainfire3D for now to play the games and then stop using it or even get rid of it once the games have been updated for your tablet. The tablet apps will be updated, it will just take a few more weeks. (I seriously doubt it would take more than 3 more weeks for developers to update their apps.) I hope this helps. Have fun with your tablet.
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