Gary, bottom line, you need to put in your distribution package all the files (save for stock files) needed on a bare system for the airports you intend to share. It doesn't matter what's in the files. If they're needed, they're needed! But you also need to consider the impact of already installed add-ons on users' systems such as ORBX, Ultimate Terrain, meshes and other wide-area scenery addons. And, unless you are going to provide an installer, those files must be packaged in the exact same way they are to be installed by the end-user, i.e., your installation instruction must be nothing more than "copy this folder there". You've got to tell the user exactly what to do and it must be simple. (And remember, even if you prepare very detailed instruction, half the users aren't going to read them so, overall, it's got to be intuitive.)
SAMM and ALFT generate scenery objects. Those objects need the .bgl files and textures those programs place for you. Re HTAI aircraft, Henry's EULA is very restrictive. In general, if you are going to include any work of others (not just the end product), you need their express permission (unless the EULA itself grants that permission).
FSX models don't work on FS9. Models based on legacy (i.e., FS9 or earlier) technology probably won't work on later versions of P3D- including AFLT's light models. Your airports must be customized for and thoroughly tested on each version of Flightsim with which you intend them to be used. (Since you ask, I have all versions of FS save for P3Dv1 - which is FSX in disguise - on my system and I test my airports on all of them. It's not a trivial undertaking, and watching AI for hours isn't as much fun as it sounds.)
Frankly, (and I don't mean to offend you), if you have to ask these questions, do you really think you are ready to share your airports - AND support them? Are you planning to provide sufficient additional trouble-free value that others are likely to use them over what's already available?
But, if you really want to pursue this, I suggest a good starting point would be for you to download airports of others of the complexity you intend and see what they've done and how they've packaged it. My airports all have installers, because manual configuration of the various combinations of static models vs AI, custom lighting vs stock lighting, compatibility with Ultimate Terrain/ORBX/etc. are beyond the capabilities of most users. Feel free to inspect my airport download archives to see what's required for a comprehensive multi-FS-version add-on airport. (The documentation includes manual installation instructions for those who don't trust custom installers.) Then, pick your most complex airport, develop an add-on package - with full documentation - and then install and test that package yourself. If after that, you are still interested, go for it!
Don