Congrats on the new purchase. That is a great boat which you and your family will really enjoy. The water could possibly be coming from the shaft packing. It may just need to be tightened up a little bit to slow the flow. A couple gallons is a little more than you would prefer but not terrible, but you really don't want enough to keep the bilge coming on and off. As far as pulling to the left, there should be an adjustment on your rudder to help with this. Play with the adjustment until you get it right. The speedo is a little trickier, although the fact that it is even reading at all is a little unusual. Can't help you there, unless you can get another speedo to try to see if it does the same thing. I guess there could be a loose wire, but I would think that it would either read or not read.
With the parking, practice and don't come in too fast. I always come in on the starboard side at an angle to the dock bc of the left rotation of my prop. When I reverse, the stern swings in towards the dock and I always have my bumpers in place just in case. The more you practice, the easier it gets. Just remember there is no steering in reverse. When I park my neighbors Nautique, I come in a little straighter to the dock, bc his prop is RH rotation and the stern does not swing in like mine. Oh and post pics of the new ride. Everyone here likes pictures, no matter the subject matter.