I recently replaced the right front strut assemby and right outer tie rod end. Problem was alleviated to the point that I could at least drive the car. However, it still shakes at speed (Can't exceed 45mph unless I am coasting down a hill), and when climbing a hill, the steeper the hill, the worse it is. Adding power to try and get beyond 45mph on level roads starts the car shaing again. It's almost like when you have really bad tires and the car shakes from side to side..but I know it's not the tires as they are only 3 months old. There is a squealing noise in the front, like a rotational sort of sqeak.

I have a split driveshaft. The one on the passenger side where I am having the problems seems to have excessive play/slop in it, especially on the inner cv joint attached to the transaxle.
I'm thinking I need to replace this right half axle assembly and do a wheel alignment.

Any thoughts greatly appreciated.

I would get the front wheel bearing (hub assembly) checked out, and at the same time replace the CV axles and inner tie rod bushings.

[EagleAutosports]

I agree. See if that helps.