When a seed in in standby, does it ever get removed from that status automatically.  Do standby seeds rotate to activity, or simply remain in standby status?

Standby seeds are waiting just like queued downloads, they are activated when an upload slot is free, usually this means a seeding limit is reached or torrent stopped manually.

Got it.  Thank you.

from what I gather, the limit is 200 UL slots and 200 DL slots which can cross over as needed if unused, so a max of 400 slots total for ULs if no DLing is going on.

If seeding 500 torrents, 100 would be left queued right? and never accessed for UL unless others are stopped.

Might it be possible to rotate files being seeded? Some priority files may be set for "constant seed", i.e. 100.
The remaining 400 could then be rotated into the available 100-300 slots, based on several criteria, perhaps giving priority to  orphaned torrents for which there are few if any other seeders. Another priority option might be the  seed to peer ratio.

I constrain my U/D loading far more than that.  I'd rather give a lot to a few than a few to a lot.  When I'm downloading, I know how pleased I am when I get a peer that is giving me a hot stream!!!  I like being able to do that for others.

I prefer a different strategy. I am not interested so much in instant gratification as I am in equitable access. Far too many do not have broadband and those that don't are ofter those dispossessed or marginalized so opening up more slots gives them a better chance at getting something. And since they are often at sub-dialup speed, they don't take away too much from a few high-speed feeds.

If I have 20 torrents active and 10 of those Torrents are Queued, Is there a way for Tixati to automatically Que a torrent that hits a zero B/s in , in order to turn on the next Que in line?

Id line for Tixati to be able to move on to other waiting torrents if the current active torrents become to slow.

Thanks

In Settings-Transfers-General do you have the 'Auto-manage slots' for Downloads/Uploads checked on?

There is a fully-configurable "advanced" box there for those slot management logic. As an alternative to churning the transfers, which honestly Tixati does very well at if you have a low number of upload slots but a high number of queued seeds...
You could always enable "constant seed" which does not use a slot for an always-on seed. You're not losing anything by keeping it active except some protocol data every 1minute.
Personally I turned off "recycle slots" and left the auto-manage on with a number of slots so at minimum if everyone I'm connected to for my upload is 5 KiB/s. This allows .5 Mib piece to transfer in 2 minutes, or almost 2 Mib piece in 5 min.