Problem after problem VIDEO

everyday I notice another problem with my bike. Can you guys tell me how to fix these problems:
1. clutch. when I turn 1st gear the bike jumps a little bit, sometimes dies, and there is this grinding noise. here is the video (notice the rear wheel, the clutch is engaged during the whole video). The guy who I bought the motorcycle from said that he recently changed the clutch. I did try to adjust the cable, without success
http://www.youtube.com/watch?v=ctwo2PBhwpA

2. when either I turn the choke on or off the engine dies, no matter if it's cold or warmed up. I have to rev the engine during engaging or disengaging the choke to keep it running

3. recently idle as well as choke RPM dropped

4. there is some delay when opening the throttle.

5. motorcycle seems to be weak, poor acceleration specially between 1000-2500rpm and like I said this delaying

 

Can't watch the video now but please tell us about the carbs. Your last few points above are classic carb issues. Can't comment on the grinding. I'm assuming you got the bike like this?

 

Sounds like you have a serious case of PO syndrome. Pull the carbs and clean religiously. Search the forum for the carb cleaning thread.
As for the clutch, couldn't tell you exactly, but it's messed. If you've got a manual for your bike, remove the clutch and replace following the manual. Good Luck!

 

When I got the bike it was ok. didn't have any of that issues. The bike was purchased 8 months ago. I haven't been using it too much. I went through the Maintenance, changed the handle bar, that's all.
What is "PO"?

 

PO=Previous Owner.

Your clutch is dragging; your carbs need to be cleaned, bench sync'ed, have their float levels checked and be vacuum sync'ed.

-Clean lube and inspect clutch cable; replace if worn.
-Adjust clutch.
-Service carbs.

 

Another problem appeared this morning. RPM dropped even lower, when i open the throttle the bike dies and then it's really hard to start it