To work properly Nuckle needs at least Coventry Nuneaton to be electrified.
You can then run a Crewe Coventry via Trent Valley stopper via Bedworth and and use the Nuneaton bay at Coventry. You could then give a regular service to Norton Bridge and Polesworth.
If Coventry Leamington was added then extend the Birmingham stoppers to Leamington to serve Kenilworth although they would have to cross at Coventry.
How would your proposed Crewe - Coventry get over the
WCML▸ fasts at Nuneaton? I think there was an underpass but it's been taken out of use as part of WCRM... Typical

However extending the present Birmingham - Coventry stoppers through to Leamington sounds straightforward, and it wouldn't increase conflicts though? They must already cross the down fast platform line, (sorry I don't know the platform numbers), as they sit in the down slow platform during their layover between services. But they already have a cunning plan to extend them all to Northampton - it's going through the track access procedures at the moment for a May 2011 start. Nothing to stop it changing again in future though. And last but not least they used to be pretty keen on running the
XC▸ Reading - Newcastles via Coventry - causing even more congestion...
Paul