But to answer your questions:
1) Yes. 4:3 is Standard def only. 16:9 can be standard def or high def.
2) FX7 but add a 3rd party XLR adapter and external stereo mic (like an Audio-Technica AT-825... or don't do the XLR adapter and do the AT-822, but you'll need the XLR adapter for good shotgoun and or lav mics...) The FX7 uses CMOS chips (which I happen to like) and it is a bit lighter.
1.On the FX7 you can switch from 4:3 to 16:9 right?
2.If you could choose which one would you get the sony HDR-FX1 or the Sony HDR-FX7?