A lot of guys have multiple charging sources connected to their banks. Charge is charge. If it says "Smart" on it, it probably has reverse power diodes in it but you may want to check. Yeah you PROBABLY could have just used a DC power supply, or even what I use for manual charging, a large Variac and a rectifier from an old stick welder, with a Voltmeter and Ammeter potected with a nice breaker or fuse block. But what you got is better, especially if like most small boats you do not have an isolation transformer. But you would not want your solar panels connected to your solar charge controller while feeding the same controller with another power supply. There are ways to do that but you can't just hook it right up like that. Solar power is just as free and useful at the dock as it is at sea. May as well use it also at the dock, instead of disconnecting it and using shore power, right? You should not really need shoreside charging except maybe to equalize on occasion, and most automatic smart chargers can't do that properly, anyway. But let's see how much juice your solar can stuff into your batts before analyzing things.
I kinda think you may be overthinking this, though I would hate to think I stifled your curiousity and eagerness to experiment. But just do what wiser heads than mine have decided works pretty good, and you will do fine. Some guys have solar and wind (each on their own controller) feeding the bank at the same time. Some use a cheapie transformer type charger and a little honda portable genset or similar setup, for making up the difference when solar is not keeping up.
A good set of panel meters installed where they can easily be read in daylight or at night is very important, and even more so when using multiple charging sources. But you should be fine. Nevertheless the more complex your system, the more you need to watch it and be Mr. Large and In Charge. Oops pun alert. Anyway, you are not really in control if you don't even know what is going on. So, meters. Big easy to read ones, accurate and dependable.
Can't really comment on your solar string as I do not yet have my own rather ambitions solar program underway yet. But there are some pretty knowledgeable guys here who will be able to speak with a little more experience on this. FWIW I have a 27' boat, 6700lbs, 5kw motor (I also have a 12kw motor, but currently running on the 5kw), 48v 220ah bank composed of 8 6v GC2 golf cart batteries from Sam's. 14x10 prop, 2:1 enclosed gearbox, 500a Kelly controller. 4 bank smart charger from Worst Marine, cause it was on sale. I pulled the old Atomic while the boat was in the water, and installed the electric drive including a motor mount that I had to fabricate from scratch, all except the prop. You don't need to do a haulout to couple a new drive to the old shaft. Prop changes in the water can be a major PITA though. Which brings up a point I want to make. Your prop is not EVERYTHING, but it is a BIG IMPORTANT PART of your NEW propulsion system. Emphasis on "NEW". A prop for sailing and occasional limited use of an infernal combustion engine is way different from an efficient prop for e-drive. If you will seldom use your electric motor for other than docking, then your original prop will do fine. If you will do a good deal of motoring then you will want a nice big 3 blade fixed prop. You can always reduce drag if needed, by turning it over with maybe 20 or 30w of power. No prob if you got solar.
Last thing... don't skimp on the wires. I use 2/0ga cable and in light of just how precious a few watts can be sometimes, knowledgeable electrical types I have shown my system to (would Chief Engineers of 120k HP ships count?) nod approvingly at the fat wire. If your wire ever feels warm, guess what? YOU are warming that wire, by expending energy IN THE WIRE, as well as in the intended load, meaning your motor and controller. You are living with a voltage drop determined by the resistance of the wire and the current, and you can reduce the resistance through the use of the proper gauge and construction of wire in the controller feed, motor phase wires, and yes, even the solar charging system cabling. It is a one time purchase, and better wire is a lot cheaper than, say, better batteries. Your connections need to be rock solid, too. Not just the terminals on the posts, but the post crimps on the wires. A lot of kits leave something to be desired on main cabling size.
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