Is there a way for a upload slot to be "recycled" if no-one requests anything from it for a set period of time?
I run 4 slots and at the moment all 4 are not uploading. I could open up more slots, but would then have to change it back later when d/ling.

I am not a tixati expert, but under settings>transfers>general there is an option to recycle unused download slots for uploading.

When a torrent is made active, it appears to seed until it goes inactive, even if there is no activity on it.  It appears as if there is no timed recycling.  When there are more seeds than the allocation, they go into standby and apparently stay there until a seed goes into completed status, at which point, new one can start.

Yep, I have checked the "recycle" option and it is useful, up to a point.
I usually have 4-5 DL and 1-2UL which can work out ok, just sometimes some of the more rare stuff gets stuck and I want to share it (if it is rare..) without slowing down the other seeds that can be done overnight.

I guess it was more of a feature request, if a seed is inactive for X time, put it to the back end of the list.

(spelling edit)

see  http://support.tixati.com/Settings_-_Transfers_-_General

Queuing
These options help control the amount of transfers that are running at a given time. It is important to not run more transfers than your internet connection and/or CPU can handle. Excess downloads will be queued and will start as other downloads complete. Excess seeding transfers will be put into a standby-queue and will activate when other seeding transfers have been stopped (either manually or by hitting a pre-set seeding ratio limit.) Both queues are fully re-orderable by dragging and dropping in the main transfers view.

The problem with this logic is that I never stop a torrent until I no longer wish to seed it.  I expect the software to rotate the seed que based on allocated up load slots in an intelligent fashion.  Sadly, with Tixati, this does not happen.

You can use constant seed option for rare stuff that you want to seed.

I agree that an option is needed to prevent stalling the queue with inactive seeds. It could be opening more upload slots temporarily if seeding speed is below set level, 50% of upload limit for example.