You might be able to get a direct or indirect ferry from Venice to Split, maybe an overnighter. I only know this from vague memories of looking at ferry timetables when I was in Split a few years ago so it might not be possible. You can probably fly Rome to Split but low cost airlines mostly run in peak season which I guess is May - September.
I've been to Rome and Munich so my pennies worth is as follows:
Rome is easy (I disagree with Abyss so long as you accept it is
very touristy so the usual caveats apply of 1, Get hardened against beggars and people selling crap on the streets; 2, If you eat next to a big tourist attraction then expect overpriced and substandard food (this also applies in London, big time) and; 3, Get to the big sites early or late to avoid crowds or buy queue jumping tickets in advance) - it is all good. The Colosseum, Forum, Pantheon and Capitol museums are brilliant. The Vatican Museums are mind boggling irrespective of your feelings on the Catholic church. Otherwise I liked just pottering around there, eating ice cream and soaking it up - I went in February and it was absolutely freezing on a couple of the days so we had lots of cafe stops for the most amazing hot chocolate ever. It was just lovely.
Munich is a bit more difficult as I didn't like it that much. Not that it wasn't a good trip - we drank a boat load of beer and ate a lot of pig and it was nice to just hang out and experience Bavarian culture but the tourist sites were a bit crap. Go to a Beer Hall because that's the whole point of going to Munich. Skip the Residenz museum, it's just not that good. That is possibly because it got flattened in WWII so whenever you look at something in a museum or an old building it says "This is a replica as the original got blown up in 1944". Saying that, the Munich City museum was good - it maps the history of the city and there is an illuminating exhibition on how/why the Nazi party had its origins in Munich. It is mostly in German but you can easily get the picture as they have the kits they used to class if people were Aryan and some stuff from Hitlers offices and what have you. The Rathaus Glockenspiel is fun to see for about 5 minutes and you can get to Dachau concentration camp quite easily if you are that way inclined (I wasn't). We got bored of Munich after 2 days and went to Salzburg on the train instead so unless you are more imaginative than me, I recommend a short stay there
If you can adjust your itinerary to pass through Florence it is well worth it! I've also been told by friends that while Venice is nice it is probably better to stay outside the city and go in for visits. No idea if that is true or not.
With regards to your driving route around the UK - it looks good but avoid the M25 around peak times (7am - 9am and 4pm - 7pm) or waste hours of your trip in traffic. The same applies for motorways around any of the major cities at peak times. Otherwise you will be grand. You will be going past my town (Hitchin) when you are driving down the A1M, I recommend St Albans as a stop off point on that leg of the journey or - and this is tenuous - if you happen to be particular fans of the Nick Frost & Simon Pegg movie "The Worlds End" you can stop in Letchworth Garden City and Welwyn Garden City and see some of the movie locations
You could also stop off in Bristol since you will be going by - it's tourist attractions are the first steam powered ship to cross the Atlantic, built by Brunel, the Clifton Suspension bridge and the city harbour area. I have lived in St Albans, Bath, Bristol and Manchester so send me a PM if you happen to need any specific local knowledge.
And let me know dates for London/Cambridge when you have them
This post has been edited by Mezla PigDog: 15 June 2014 - 04:12 PM