Semi retirement and my mortgage

Semiretirement

Hello - first post here so I hope you bear with me.

i am able to take my pension aged 55 in June, and return to work contributing to another pension scheme on reduced hours. The new pay combined with my monthly pension will be roughly the same as my current income. I have a Help to Buy loan which I intend to pay off in June, in recognition that the value of the house has grown in the 3 years I’ve owned it. My current mortgage fixed rate ends in October. 

Hope that’s enough background!

my questions are-
1 -  I have been told by a financial adviser that it’s best not to mention to my current lender that I am retiring and returning to work as this will make them nervous about me as a borrower in October. Is this correct?

2 - when it comes to seeking a new fixed rate, is the LTV % improved once I “own” the 20% portion currently “owned” by the Govt or will it make no difference? If I pay off the 20% before October will that improve the mortgage products available to me?

3 - in order to get a new mortgage product with my current lender would they do a valuation? When I got a new product last year they didn’t revalue. 

4 - after paying off the Help to Buy loan, I will have some left of my pension lump sum. I am keen to use it to get my monthly mortgage payment down, so I am wondering if there is a calculator or formula I can use to work out exactly how much I would need to pay off to get the best rates on a new product?


I am hoping these questions are ok. I do plan to pay for financial advice as this is a big decision for me, but I just wanted to be a bit better informed before I speak to anyone. 

Many thanks