Well, let's say my pump was making more than just a squeal, kind of a horrid grinding noise that only got a little quieter when filled with new fluid. That plus all the fluid residue covering most of the lines and the box as well, and a milkshake like coloring of the fluid inside the system made me want to replace everything. You said you need to fill the reservoir from time to time, and it still doesn't have power steering, and the steering feels loose, lots of play in the system?
I would do as mudderchuck recommends and have someone turn your wheel side to side to check for worn tie rod ends, ball joints, check the steering box for play and leaks, lines, pump, everything. When I replaced my parts I noticed some loose hardware on the tie rod, the bolts on the adjusting coupler, tightening that helped me lots! It also made me realize I need to really go over my vehicle for my own safety and the safety of others, I would hate to loose my steering at 70 on the highway!