It really depends on what you want out of it, mileage; routes you haven't been on before; new traction, Loco haulage (probably not based on that itinerary) or something else?
There is an awful lot of Voyager mileage there, if you don't hate them now you will by the end of the 2 weeks!
I agree with what Tim said, look at spending a few nights in hotels if possible, you won't have to spend half the day shuttling to/from SOU so can get to more spots and trains you wouldn't normally be near.
Are you planning to book sleepers for any of those overnight runs or are you going to use the seats? If the latter then expect to be getting **** all sleep and 2 of them in a row may leave you rather worse than you think, you may find you don't enjoy the daytime trips much due to nodding off. You may also find yourself having to sleep in on one of the later days short to catch up on sleep when you do get back to your own bed. It may be that you will have no problem sleeping on the seats but you would be in the minority.
I am sure that you are avoiding hotel stays for cost and I can appreciate that, I did the same when I was younger but TBH spending numerous nights not sleeping on overnight seated trains was not at all fun and I would have enjoyed my days much better had I not been knackered for long periods.
Other small things like instead of going to/from the same station look at walking to near stations to get a different line in, Bradford FS - Interchange for example. Instead of going back and forth on the Barton branch look at going to or from Hull by bus over the Humber bridge perhaps.
They are just my thoughts, not a criticism of your plans in any way.