Remortgage Queries

My other half and I are about to take out a joint mortgage. She had an issue with a default several years ago due to a mobile phone being stolen and a big bill being run up whilst she was at university. Despite multiple attempts to get this removed from credit record it wasn't possible. After discussion with some mortgage brokers we have been recommended someone to use given our situation, which I am happy to do. The rate is slightly higher than a competitive high street rate, which again I don't have a problem with given the situation.

The deal they have recommended is over 30 years, I will have a chat to the broker tomorrow to see if it makes much difference in terms of likelihood of being approved if the term were cut to 25 years, but I had a question re terms at remortgage.

I still have to go into what the tie in period is (the recommended product is fixed rate for 2 years) and what fees apply to switching providers after the tie period.

So my questions are what are typical tie in periods for fixed rates for 2 years? What are typical fees for switching after the tie in period?

And if when you come to switch you have 27 years left on the mortgage, can you decrease the term to 22 years (ie effectively making it a 25 year mortgage) if you can afford the repayments at that point in time?