There, I hope that was more thorough. Usually I worry that I write too much in these things.
Don't worry about writing too much. When it is useful, as yours is, it is well worth the bandwidth. What you revealed about your loading style and shooting aspirations will allow us to target our advice much better.
Do you have a chronograph? I would suggest one before replacing/upgrading any of your loading gear. Get the kind with the sensors downrange and the readout on the bench. Much easier to use.
If you want to replace your RCBS Jr, with a heavier-duty single stage press, the RCBS RockChucker is good if you are brand-loyal, but I would lean toward the Lee Classic Cast because the spent primer handling is better and the new primer system is easier to load. If you have the budget, the Forster Co-Ax
is worth a look (about $200). Then, there is the Redding Big Boss. Lots of leverage.
You already have my thoughts about the Lee Classic Turret, Dillon's SDB and 550 offerings. Just remember, the Square Deal press will require Dillon's proprietary dies. All the other presses mentioned will take standard dies.