Question about account guild
Being in a guild is account wide, so alts shouldn’t take up an additional slot. You’ll have to open the guild window and click the Represent button for new characters though. At least I don’t recall if it does that automatically.
+numerous alts of varying levels
Salgari is right. You can be member of multiple guilds, membership is always account wide (so whatever character your on it will be visable in all the guildrosters). You will always only take one spot in the roster. each character can decide to represent no guild or one of the guilds your account is member off. You can only representing is characterbound (so with different characters you can represent different guilds).
so short answer to you question is NO
I do hope my clarification helped you to see the mechanisme behind guilds. It is rather difficult and technical, but off all the mmo’s I’ve played for the members its the best.
Arise, opressed of Tyria!