The plugs took me about 6 hours. It was my first time. The Drivers side is pretty "easy" per say. I have a long extension(s) and many types of universal joint socket set adapters. After some thought, I believe I had my son reach his little hand in the front right to get it started. I always make sure to start all my bolts by hand. Just be patient and take your time. Wish I had recorded how I did mine. I believe I did the Front two drivers side from the top. The front passenger side from the top. (this one I got a 2x4 and pushed the lines there slightly out of the way with caution. Removed the intake and coolant reservoir. The backs and mostly did from the bottom. I would highly encourage you to change them. Mine were absolutely shot. The scuttle butt on the forum is DO NOT USE the BOSCH spark plugs. There are several different preferences here on how to gap them. It is super charged so that is a bit different. Something about blowing out the spark. I had to change mine. Rats ate into the spark plug wires, one of the wires was barely on. I honestly do not know how it was getting any spark. I am not worried about doing it again when needed.
#1 Make sure you wear some good googles or safety glasses underneath. These things are old and all kinds of crap will get in your eyes.
#2 To answer your other question I put the Permatax flange sealant on top of the super charger and at the Intercooler/tube connection. I just get the nuts snug. I did not put any on the connector that requires the special tool. I cleaned all the surfaces on the tub with my dremel polisher. The scuttlebutt on this forum is that this sealant will not destroy your super charger is some gets in it. Black RTV will. I just do a light 1/8" bead around. Also, while it is drying I make sure to lossen and tighten the bolts on top of the super charger to be sure they do not get ceased up with this stuff. Thats what happened when the guy before my used black RTV. I honestly have been running it for about a year without any sealant. My buddy who does super chargers alot says it really affects your gas mileage so I just put it on tonight. Internet says about and hour to dry because it hardens in an oxygen less environment and contact with the aluminum. Sorry for the long post. Hope this helps.