1. What kind of homun S, and is it being AFK leveled or actively leveled?
2. As far as I know, there has been no change to the homunculus leveling system or cap.
3. Huh?
4. Consult the documentation for the AI you are using - this is generally provided as a configuration option. ( If using AzzyAI, it's UseOffensiveBuff and UseDefensiveBuff for pre-S homun skills. )
5. Consult the documentation for the AI you are using. Most AI's have a feature to "friend" another player - this has to be done in a different way than adding people to your ingame friend list, since the AI can't read the in-game friend-list. (If using AzzyAI, you move the homun 1 cell directly north or west of another player, and it will do a little dance around them to indicate that they were removed or added) Some AI's also have ways to enable kill-stealing either globally or for specific monsters. (If using AzzyAI AzzyAI this can be set on the tactics screen; if you have tactics defined for the specific monsters you're fighting, you need to set it there, not just in default tactic. )