Gap in electoral register, student linked addresses: Credit for Mortgages

Ingah

I'm looking to take out a mortgage soon but my credit files have shown up some minor things which concern me and I was hoping someone could advise if I should try to correct them, and if so, what's the best way (i'm signed up on the free trials at Experian&Equifax and the free for life at Noddle):
1. A 3 year gap showing in the electoral register from 2010 to 2013. I'm currently on the electoral register from both 2008 - 2010 and 2013 - Present at my current address. I have lived at this current permanent address since 2008.
2. I'm seeing a few linked student addresses from when i was a student 4-5 years ago and unwisely registered a bank account at the student addresses (it was never a permanent address).
3. One incorrectly linked address (i.e. flat number was wrong) and another link to that same incorrect address, with my name incorrect...
4. I have the wrong "time at address" showing for a credit card application made about a year ago - it shows 3 years instead of 7.

I was also wondering how to fill in a mortgage application regarding the student addresses, as i've been living in my current address for 7 years and I never 'moved' to the student addresses (i was back at forth, but mainly at my current address), but they show up in my credit file and i did move one (of my many) bank accounts to them...