PA28R-200 speeds
No disrespect intended, my friend, but don't you have a POH for the airplane handy? It would have recommended speeds for the maneuvers. Of course, you can use Va or less.
I remember that in the Arrow I flew years ago that although my instructor said otherwise the POH said you were not supposed to set 25-square for climb power. You were supposed to set 23-25 for climb power. 23-23 is a good rule-of-thumb cruise setting. You can try 15-18 inches for descent power. Of course, you don't want to go below the bottom of the green arc on the MP gauge.
To set up for flight at critically slow airspeed (MCA), I reduced power to 15 inches, and during the first clearing turn at flap range I put out the first notch of flaps, during the second the gear, and coming out the turn the rest of the flaps, moved the prop lever full forward, and added enough power to maintain just above the horn. Of course you're maintaining altitude and heading per the appropriate PTS standards.
For stall recoveries, recover as with any other airplane. Release back pressure enough to break the stall, full power, pitch 5 degrees (whatever puts the cowl on the horizon) and flaps 10, raise the gear, positive climb, and raise up the rest of the flaps slowly with the Johnson bar. Of course, you are holding heading +/- 10 degrees or whatever the PTS says. Same basic procedure for go arounds. Lead with pitch up, full power, flaps, gear, flaps. When I think about it, it really is very much the same as with a Seminole.
I remember that it was easy to flood the engine during startup if you weren't quick enough shutting down the electric fuel pump during priming.
The airplane is really basically the same as the other Cherokee derivatives that I'm sure you've flown, after I viewed your profile. Maybe a little easier to land because it's heavier than a Cadet (Warrior) or Archer. I always thought Piper was easier to land in a crosswind than Cessna.
Hope this helps a little. The Arrow is a nice instrument platform, by the way.