sale of the primary house in the UK does not attract tax so will maximise tax efficiency via the interest from the capital investment. Get some ISAs on the go before leaving. SP in 9 years so that and the tax free interest should keep us ok. Assuming tax allowances increases to match SP value. You won't win elections if the SP becomes taxable! That would be as popular as the short lived Poll Tax!
It's a 5 year visa journey to the UK for her, if you get married and want her permanently residing with British Residence Card (BRC) and meet the financials.
Otherwise a 6 month visit visa every year, if the visa rules are not broken and financials are met.
I brought my then Thai GF over for the summer months, then visited her during our winter months.
We got married here and went down the 5 year residency route so she could work, pay taxes etc. But we are now both heading to Thailand as UK has lost its way a bit and forecasts are not favourable unless you love paying taxes!
The IO comments are final..has he/she written anything on your passport stamp? But it is a bit harsh..I came in 1st January on 60 days then left 31st January and came back 3rd March no problem.