LISA or Help to buy

Sordello

Hello everyone, was wondering if anyone could advice on this.

I am a first time buyer, I have both LISA and Help to buy ISA savings account. When it comes to purchasing I am considering using just the LISA for my 10% deposit (in order to benefit of 25% from the government). I am aware that the help to buy ISA cannot longer be used for purchasing (however I have been using it as a saving account).

My question is could the money, saved in the help to buy ISA be used for solicitors fees etc..or will it be exclusively for the house purchase.

If it is so would be advisable for me to transfer all the money into the LISA account or close the help to buy ISA?

For contest 
Say I have 10k in the help to buy and 20k in the LISA account. 

Would transferring the help to buy into a regular account and placing into a higher intest rate/cash isa get a greater gain or leaving in into the help buy with the accumulated interest be better? So that  money transferred from the help to buy may could be used for solicitors fee etc...