A few things to consider from my limited experiences.

1.) adding FHM now is a good idea, but they will need the pallets in the water to really multiply well. I would suggest floating maybe 10 of them with ropes that are anchored at full pool so you can control them as the water rises. SIDE NOTE: I'm not sure about what temps they require to spawn, so check that out first before stocking them.

2.) Your pallets structures will need to be anchored and/or weighted down or they are going to wonder off on you. The FHM's will dwindle as the first few years pass. I am on my third summer with the minnows and the second with HSB and HBG and the FHM populations is a small fraction of what it was the first year with out any predators. I strongly suggest giving the FHM's a FULL year to do their thing...you won't regret it. My 1/4 acre pond has over 20 pallets in it (several stacks of 2 to 3 pallets each...maybe overkill but they produce many YOY) I'm not sure if I will take them out or not once the FHM are extinct (probably not as they will still add structure for the fish).

3.) I believe you will want more then just RES in the pond, maybe HBG and/or YP too. IIRC, RES only spawn once a year where HBG can pull off multiple spawns and your HSB will want more to eat. You could easily add 3 to 400 HBG to your stocking plan or consider YP in the mix.

4.) You should do some more research on the intake level of your fountain. I would be concerned that a deeper intake might be bringing up dead water and making the upper water conditions worse. Fountains are good for aesthetics and surface aeration and neither require a deep intake. At least with bottom aeration systems, you want to turn the whole body of water over once a day to keep ahead of the lowers water column from stagnating...I doubt a 1/3 hp pump is going to do that. Something to verify as I'm no expert in the matter.

5.) The creation of habitat (submerged tree) is not a necessity and it depends on your goals and how the fish populations balance out. The fish like to hang out around such stuff and, if it's dense enough, small fry can use it to hide in and grow larger so they can become snack for larger fish.

6.) Hard telling about your well. An expert might be able to guide you. All I can say is...if your watershed is large enuogh, a few good rains and the well is not needed. You'l have to evaluate that and balance it with your patience and risk acceptance.

7.) Docks are a funny thing. If your confident in where the water level will stabilize, a fixed dock is great especially if you can get it in before it fills. I went with a floating dock for fear that my water level would fluctuate and I used rather flat rectangular floats (purchased from Menards). Barrels can be used, but can be less stable...the dock could have more wobble to it.

8.) Optimal fish feed can be purchased online and delivered to your house for about $55. It's real good stuff.

That's all I got for now...Your pond looks fantastic and welcome to the forums!

Fish on!,
Noel