I fed my entire panel from the top and bottom, so it is doable as long as you plan well and double-up wires through cable clamps. But you are going to need some way to secure wires within a few inches of the panel, so a 1x board set in between the studs may be wise. You are going to end up cursing having put it in between the studs as access is going to be a PITA. But it will look prettier in the end!
Unless you have a local code requirement on # of boxes per circuit, there is nothing in the NEC about it. The rule I am aware of for commercial work is 13 receptacles on a 20A 120V line. But only commercial as there are no requirements in residential for this. Modern houses can get crazy with the number of circuits in them, so you do need to pay attention when planning this so you don't run out. Not putting enough on a circuit can cause you more problems this way.
I have found it much better to separate outlets from lighting. You group together a large section of room lights on a 15A circuit, and then a room or two of outlets on a 20A. The main reason for this is lighting loads are really very light (pun not intended, but I'll take it...) plus the fixture wires are very often these super tiny 18ga (or worse) things and they do NOT like to cooperate with a beefier 12ga romex wire. Lights are also fairly fixed so you can figure out how much load you have and be pretty solid on it. Outlets can get anything plugged in, so it is safer to go up to 20A for those which also makes for fewer nuisance trips. Judging by what I see for your house layout and size, you could probably run 2 or 3 lighting circuits to cover all your lights. Being new you are probably going to have LEDs pretty much everywhere and they draw nothing to speak of.
Count up the number of 220V breakers you will need. Typically well, AC or heat pump, stove, oven, water heater are the things to watch for. If you have all of those that is 10 spaces gone which is 1/4 of your total in a 40-space 200A panel. If you run a subpanel from your main, that is another double. Then you have the required dedicated single pole circuits - kitchen x2, microwave, each bath gets one, laundry. That is 6+ more spaces gone. It gets tight in there pretty quick...