1. If not luxury 裝修 the price may not have much diff. If there are fixed furniture depends on luck as the design may not suit everyone.
2. Bear the risk of not receiving rent also may need to pay tax. Moreover do not expect the price will always rise.
3. This may be the best move! I believe your flat should have certain accrued profit and you may cash out.
If the cash flow allows you may buy another new flat as there are some developer still providing 2nd mortgage. (RC still has 1 3-rms at blk1 45/f at 3.25M...)