For a Microfranchise, look at the North East section of Northern. That would be decent as it's kind of out of the main area for Northern so a micro franchise there might work.
I would like to see less silly long routes which have little-no purpose and move routes about to operators which now make a little bit more sense.
For example give Bristol to Portsmouth runs. From Southampton to Portsmouth it's electrified so should that really run with an EMU. Southampton to Bristol should be under SWR as I think it just fits their network better with them already running at both ends of the line, it just acts as a connector then for their network. Also rid Brighton trips as I don't think they would be used much, it would make a lot more sense to have them being ran by an EMU either changing at Southampton or Portsmouth.
Some more Open Access operators working with the main operators would be good like the Stourbridge Shuttle line. Ran as OA but has WMT branding and works as part of the main network. Island Line, Lymington Branch and Barton to Cleethorpes is where I could see this approach working maybe. Very locally ran can improve passenger numbers and make passengers happier. Why not do that if it can be done.
Thirdly, stop putting in silly TSRs for operators to stop at stations they would never normally call at. TPE between Doncaster and Scunthorpe this is aimed at but surely there are other examples. Just put an extra service in the primary operators TSR.
Finally, have a national RRB database and put everything though 1 system. I say this because it was well noted a while back about how some Rail Replacement firms were taking their time (to put it nicely) to pay the bus operators. Also, the more people on the database, the more cheaper the tenders might be (as more competition makes prices cheaper) and it means TOCs can't be as biased towards their own companies therefore profiting twice. Arriva using Arriva buses or First using First Travel Group to arrange the RRBs.
For stations, I would like to see 2 things happen.
firstly for PTAs to be offered the chance to take on the stations (as Merseytravel heavily invest in the station but feel they don't get much back from them)
Secondly, give control of the stations to the main operator. Not only are some stations managed by companies who don't even serve the stations but other stations are managed not by the main operator (Alnmouth and Chester-Le-Street come to mind).