Looking at GitHub code, I think play status works in tvh4.2.
https://github.com/tvheadend/tvheadend/blob/release/4.2/src/htsp_server.c
Line 2857 suggests to me that if you have an old version of Kodi it will do server status automatically (marking a programme as watched).
If you have a "new" version, then Kodi pvr.hts has to set the play status itself and can also set the "resume point". Is there a setting in Kodi pvr.hts for this in version 17? In Kodi 18 it works (pvr.hts advanced settings, "server based play status").
For automatic delete, that should work in tvh4.3 regardless of the version of Kodi that you have. But, if you decide to upgrade tvh, remember to take a backup first since some of the config files have changed and so it may be difficult to switch back to 4.2.
Perhaps for the widgets you can raise a bug (or a question on their forums) to see if they can support a "long press" menu. The functionality of widgets is relatively new, so what you ask seems a useful addition; or perhaps they can suggest an alternative way.