For me the best answer would be:
5) Franchises include local and longer distance services.
Instead of having some lucrative franchises that should generate big premiums/ big profits (WCML, ECML) and some which need massive subsidies (Wales & Borders, Northern), why not combine the two types of operation into one?
That way you'd probably have every franchise requiring a low subsidy/ paying a low premium (rather than some requiring large subsidies and some paying premiums) which means a lot less risk of the TOC walked away during a franchise.
At the moment it's meaningless to have some TOCs paying big premiums whilst others take big subsidies - the overall cost/benefit to the UK is what matters.
The fact that this coincides with my general view of operation (that it's much more efficient to co-ordinate services and to give the longer distance operator an incentive to connect with local branchlines etc) is pure coincidence of course
GA/ SE/ SN/ SWT/ FGW and FSR all seem to work well like this. It avoids a "two tier" workforce (allowing natural progression in the company, rather than Unions playing one TOC off against another). It encourages a stable use of stock/ paths/ investment.
The problem is that it would mean franchises were no longer so attractive to the likes of Branson, who only seem to want to lend their brand to the exciting/ fast services, but is that really a reason to keep the current situation?