Second Charge on property in the uk?

I have a few questions;
Does having a second charge on someone’s property count as assets or capital?

Does this affect benefits?

Is this recorded on your credit file?

I want to put a charge on someone’s property for £65,000 in the uk please advise and also do I declare this as I technically only get the Money when and if the homeowner sells.

What are the IT benefits one can avail on a second home ?

i bought a flat 5 years back in banglore and a loan running for 20 years ( another 16 years )- its a joint loan between myself and spouse. Now i picked up a small villa property only land in a gated community . should i construct a house , rent it or move in . a bit confused. is it a good investment or another flat was a better investment . i need to another loan of around 25 lacs .