Modding FM is a pretty complicated business, especially because there are 3 main versions of the game. There is 0.985, The Git version and Jimbobvii’s version. I would recommend either 0.985 for the easiest compatibility or Jim’s for more base game features and faster run time.
I think Nostradamus’s mod is mostly comparable with other mods, it doesn’t change any of the base game files. It does run into some issues with Jimbobvii’s version due to how fat is calculated in that version but otherwise works fine.
A) It isn’t worth installing any of the mods in the legacy section of blog as most the content there is already implemented into the game. That leaves Dohavocom’s mod and Nostradamus’s mod. Technically they are not compatible but they mostly work together last I checked.
A2) Maternal-Reads mod is a pretty heavy duty mod as far as what it changes and it comes already in a package already installed, so if you are using that mod you basically have to start with it as the base mod. You might be able to get away with Nostradamus’s mod on top of it but it probably isn’t worth the effort to install Dohavocom’s mod on top of that.
C and D) I think so, there is also Feedee Paradise mod v.1.4.10 (01-11-19) - #11 by Sekeis which is an extension of Dohavocom & Juxtaterrestrial mod. There may be some issues if you install Nostradamus’s mod on top of that but it should overall work.
E) Nostradamus’ mod has a witch you can meet after visiting the brothel enough times that eventually gives you a spell to increase size.
I’ve had varying success with multiple mods at the same time. The more the mods change the same files, the less stable the game gets.