I agree with Bry and goldslinger.

The wobble or shaking is probably caused by an imbalance in the flybar or shafts.
I would take the inner shaft and upper head off the heli and spin up the lower rotor only. Check for a wobble or shake by looking down on it from above. If it does not spin true then the problem is with the lower assembly/outer shaft.
If it is good then put the inner shaft/upper head back on and spin it only, check for wobble again.
That should help pinpoint the problem.

Also, in moving to the aluminum lower and swash, your swahplate is probably way out of "level", causing directional movement.
You need to level it by lenghtening or shortening the pushrods (linkage from servo arms to swash).
You can eyeball it first by trying to make it level with the rotational plane of the lower blades.
Then when you are able to hover again, if you have forward motion, and your COG is OK, the LEFT pushrod needs to be shortened.
Backwards movement = Left pushrod needs to be lengthened.
If the heli moves/banks to the left then the RIGHT pushrod needs to be shortened. And movement to the right = Right pushrod needs to be lengthened.