Questions:
1) Do I even need the XP mode software or will Liquid 7.2 run okay directly under W7?
Liquid will run directly under W7.
2) Regarding TDK. Will the original TDK RT run within the XP mode software?
The RT didn´t work with Vista, I haven´t tried with RT and W7, I know that TDK Pro works very well.
3) Should I uninstall Liquid 7.2 and reinstall within XP mode software... is this necessary?
No, just follow the install thread, sentence by sentence
4) TDK Pro... should I uninstall and reinstall or will XP mode pick it up? Is the XP mode software even necessary or will it run under W7 professional as is.
as above, the install thread
Finally and unrelated: I updated with 7.21 Direct X software but no matter how many times I have done so the Liquid shows as 7.20 build 4296 SP1 4345. Do you know why this might be happening?
that is the correct version number for 7,21 if you only have 7,2 , the version number is 4296 only