gramdeck

depends on the version of wow  you play... take a look at other FC's that use it and implement it in yours.

IIRC Droidz put in an option where is a FC has <25 yd range it will trigger auto attack and if its > 25 yds it wont trigger it.
You would need to write the FC in C# and put a range clause in it.. If you are still keen take a look at my vanilla Hunter FC and look at the range function and change the options to be Mana driven so if you have  <10% mana the range is 5 yds so the bot auto attacks.
 
Ideally... gear / set the bot up so it wont go OOM or set up wanding for low mana situations.

Hello, in spell condition you have option "Global Cooldown Enabled"

You can blacklist vendors (tools => blacklist), remove them from your profile (if that's the source).
You cannot set a main vendor, but you can set your profile to ONLY use vendors from your profile, not your Bot's database.
In a quester profile, it looks like this:
<QuestsSorted Action="RunCode" NameClass="wManager.Wow.Helpers.NpcDB.AcceptOnlyProfileNpc = true;" />