The Loadmaster was not designed to perform as you wish. If you decap at station 1 then fill with powder at 2 the powder will trickle out of the primer hole on the way to 3.

I reccomend you use whichever brand /style loader as they were designed to be used at least untill you get a few miles under your belt. I use the loadmaster but rather than performing additional operations I oft times use the case loader to speed the process but actualy use 2 or 3 passes in performance of the overall operation.
1st pass to deprime and size prior to cleaning. 2nd pass to prime although most times I hand prime while watching TV. 3rd pass for powder bullet seating and crimp.

Priming can be problematic and in the long run I find the overall process is faster and more reliable when performed in multiple passes.

Good point about using equipment the way it was designed.

I like your method of depriming and sizing prior to cleaning. You probably get rid of some of that powder in the primer hole.

Why do you not do priming, powder, bullet, and crimping in a single pass? What type of problems do you run into during the priming step?

I suggest that you do not need a powder-check step.
As long as you keep your full attention on what you're doing, you won't skip putting powder into the case.

If you're firing semi-auto cartridges, the roll crimp that the bullet-seating die forms is incorrect. It can also be unsafe.
Semi-auto cartridges headspace—that is, are held in their proper place within the gun's chamber—by the circumfrential ridge formed by the edge of the case's mouth.
The roll crimp is the wrong shape to properly accomplish this. A semi-auto cartridge requires either a taper crimp or no crimp at all.
Revolver cartridges can be roll crimped by the bullet-seating die, since they headspace on the case-head's rim.

A taper crimp must be formed by a separate, dedicated die. If your press does not have a sufficient number of stations to permit the use of a taper crimp, then either do it separately or don't do it at all.
If you elect not to crimp, the case-mouth expander must be very carefully set to just barely expand the case mouth, to permit bullet insertion without bullet damage. (The best bullet to use, then, will be one that has a slightly chamfered bottom edge.) The results will be a bullet held in place by the friction of a tight case mouth, and a ridge on which the cartridge can headspace.

I disagree with your sequence of events, using any press. The proper sequence is:
1. Feed the case (by hand or machine),
2. Outside resize and decap, then prime (re-cap),
3. Bell the case and feed the powder,
4. Feed the bullet (by hand or machine),
5. Seat the bullet (and possibly roll-crimp the case),
6. Taper-crimp the case (if it hasn't previously been roll-crimped), and
7. Remove the loaded round (by hand or via a ramp).
Items #1, #5, and #7 are not normally accomplished at their own separate stations, although the Lee set-up, specifically, may require it. (I have no Lee experience.)
This means that the "normal" progressive press would probably have either four or five separate stations, at which are accomplished items #2, #3, #5, and #6.