1. Correct. And, may not even run with Snow Leopard.
2. All the listed applications can be updated:
Adobe CS4 and CS5 should work as both are, I believe, Universal. At least CS5 is.
Office 2004 can be upgraded to Office 2011 which works fine.
I believe Adobe Acrobat 9 Pro is Universal. I have a copy that works.
3. Whenever you upgrade you have the potential need to spend money on software upgrades. What's new about that? If you don't want to, then just don't upgrade. Or, go slit your wrists. Your choice.
Select any of your CS4 applications. Press COMMAND-I to open the Get Info window. Where you see the word Kind: look in the following parentheses for the word Universal or Intel. If you see one or the other then they are compatible with Intel processors. Do the same for Acrobat 9. Only your Office applications will have "PPC" in the parentheses.