re: Votes
Google on 'uk expat right to vote'
Lot's seems to come up, including...
http://www.euronews.com/2016/02/27/as-a ... eferendum/
'How British expats can vote in the UK EU referendum'
But re: that precise sub-topic ^, the government went to some lengths last year to exclude expats voting in BREXIT (wadda surprise). Your rights to vote in UK elections run deeper than just the to-and-fro over the BREXIT vote though. Your ex-local council www should detail how to register. Worst case your MP can likely help. Either way you then appear on the UK electoral roll.
And, you can nominate say a family member to 'proxy' vote on your behalf*. But then that only works if they live in or near your electoral ward. I.e I could have nominated my father, but he's not going to drive 300 miles R/T to cast my vote. Hence making my MPs assistant, aka 'agent', my permanent proxy. That strongly incentivised my MP to help me get the necessary forms and file them for me, which made the job easier...
* You can apply for a postal vote, but the turn around time required is potentially so short, that was IME/O simply not a viable solution, at least not from Asia.