1989 21' Renken Restoration project

[MilitaryPopo]

I purchased a 1989 Renken early in the summer and used it many times over the summer. I knew when I purchased it that I would be renovating the entire boat during the off season. I have removed all the vinyl and backings, windshield, engine cover (i'll be changing the design of the rear of the boat, removing the jump seats and installing a bench seat in front of the engine), the two fold out lounge seats (i'll be installing 2 captains chairs in their place). The first questions I have now (probably first of many), I cannot get the steering wheel off the helm(?) post. There are several soft spots in the floor, I have not removed the carpet yet, so I'm not sure what they look like, is it ok to cut out the soft sections and repair, or do I have to remove the entire deck and replace? I read somewhere that hull painting needs to be done by a professional (something about the gel coat and chemicals), is it possible to paint it myself with an paint sprayer? One of the main issues I had during my excursions is that the engine had a tendency to stall out when placed into neutral (more so when it was cold) and also when first launched I was never able to use reverse because it would also stall out then. Once the engine was warmed up I didn't usually have a problem putting it into reverse. Lastly for now, the engine has no hydraulic steering (I have a 350 ENPAC 260hp aftermarket engine (1991 I believe) with an OMC Cobra? outdrive), is it possible to add hydraulic steering to this boat and if so, how expensive will that be? I know this is a lot to ask, but I'm fairly new to the boating world and appreciate all the help I can get. I'm pretty good with most things construction, so I'll most likely understand any points you can give me.
Mike