Dont get it wrong that every borrower is quailfied for 90% loan. The % is depending on the bank after evaluating the purchase price, borrower income and his other loan commitments (HP,  PTPTN, PL, & CC).

In addition, every borrower must engage a valuer to conduct a valuation exercise on the subject property. If SnP stated eg 500k and report is 460k, then % loan is based on 460k. How much purchaser marked-up is not the concern of the bank.

Any shortfall in loan have to be paid by the purchaser borrower b4 the bank release the money.

The cost of purchase (legal fees, stamp duties & valuation fee) is about 4% of purchase price. In addition, borrower is require to purchase insurance to cover the loan amount which is quite a substantial premium.

If you managed to mark-up the purchase price and have it approved, then ok. Any excess money from the marked-up will be given to you by your lawyer after the completion.

If you sell your house, you will get the money similar to how you and your bank pays the seller. If is freehold, it should be within 3 months. Leasehold will be around 6 months.