Tranny problems please help!!911 white man down

I recently as of 4 weeks ago bought a 1995 Mustang GT. it has a T-5 tranny with centerforce clutch kit in it looks new. notice that my gear shift would vibrate alot and would feel a vibration in car. changed the U-joints. and noticed no change in vibration. was going down street at normal speeds then all sudden I heard a chattering noise comin from tranny area and it poped out of gear and wouldnt go into any gears. then I put it in nuetral. for sec then up into third and drove it home. tried out 1 and second gear onced I got home and worked fine with no noise. put it in nuetral in driveway and after about 1 min I start hearing a noise comin from clutch area of tranny. I jacked car up and noticed the throwout bearing stays in middle of clutch all the time. and while jacked up I cranked car and can hear a noise chattering comin from clutch area. any clue what could be wrong? also when I mash the clutch in I hear no noise even while reving the motor.
 
I jacked up the rearend today and noticed a vibration on drive shaft and the engine moving a little from side to side and tranny vibrating. not shure if its normal my engine is a 306 with E303 cam and GT-40 upper and lower so im assuming with the cam ill get some vibrations. I had the U-joint replaced on the drive shaft the one that connects to the yoke but didnt have one replaced that connects to pinion gear. I drove the car down the road a few times drives good but still hearing noise and gear shifter vibrates. all the tranny shops around here want you to bring it to them and them pull tranny out and find something wrong with it regardless. so i dont trust them. I have limited funds and would like to find the problem on my own without un-needed costly repairs. Im gonna do a youtube clip from under car and link it here later if possible im desperate for a solution. also checked the motor mounts and balancer seems ok.
 
Do you know if the person who sold you the car put a tranny in it? Because if the transmission is from 93 or older the T5 is different. 94 and 95 input shaft on the T5 is longer. So the input shaft will not ride on the pilot bearing and cause a vibration. Hope this helps you out. Good luck