London - 6 days
Paris - 6 days
Venice - 2 days
Rome - 5 days
Plus travel time
I can't really change it around much anymore, but I was wondering is this realistic? Will I be able see/do enough things while I'm there without being too rushed?
You can spend a lifetime exploring any of those places. What you have to do is accept that you have a limited time and compile a "must see" list, in order of priority, for each place and do your best to see as much as possible on that list without falling into a box ticking exercise of only spending 20 minutes at each site.
plenty of time. maybe add a day to venice and take one off of rome. just my opinion. if anything else, shave one day off of London and add to paris and travel outside the city. have fun!
sure, i have been doing this , even for 2 weeks on the same itinerary from Sudan to Europe because of shortage of holidays.
Make a list of what you would like to see and do and how much time you would like to spend there and that should break it down for you.