Regarding the present Liverpool - Norwich service, ideally it would run via Dore South curve and Ely West curve, so as to eliminate the train from reversing direction twice.
The Liverpool Lime Street - Sheffield Midland common section could be every 30 minutes, with an hourly service to each of Cleethorpes and Hull Paragon. The present Leeds City - Sheffield Midland and Nottingham service could be increased to run every 30 minutes along the entire route, to compensate for the diversion of the Norwich service via Dore South. At the eastern end, the present Norwich Thorpe - Cambridge service could be doubled to every 30 minutes - perhaps an extension to Stansted Airport, so as maintain the same frequency between Norwich and Ely, and possibly improve the level of service at some of the stations east of Thetford. Furthermore, by extending the Birmingham - Leicester London Road service to Anglia (possibly Ipswich), this would compensate for the Liverpool - Norwich service being diverted via Ely West curve, and maintain the same level of service between Peterborough and Ely. By continuing the extended service to Ipswich, it would restore direct links between the Midlands and Ipswich, and combined with the short Cambridge - Ipswich AGA service, would improve the frequency over that common section of route.
Obviously, this would mean 3 limited stop trains per hour between Liverpool and west of Dore & Totley station via Warrington Central, which would most likely be tricky to slot in if a 30 minute frequency is maintained between Liverpool and Sheffield. It looks like we will have to make do with the Liverpool - Norwich service and Manchester Airport - Cleethorpes service in their present form for the foreseeable future, until somebody comes up with a better suggestion and knows what they are doing.