yes its true you apply for the MEU1 and its currently without an expiry date you can after 5 yrs provable legitimate residency apply for MEU3 permanent residency
Not quite as long as you have the yellow slip before B day (Bidet) the Cyprus Government have said that you will retain the rights to stay under the withdrawal agreement/deal, however they havent stated clearly what their plans / intentions are under a no deal scenario..... any newcomer to the island post Brexit would become TCNs and treated differently in terms of MEU1 residency applications ie the requirements are different for residency ...plus who knows what else????.. also think about if you need to work and may need a permit too - medical / healthcare requirements S1 reciprocal care, driving licences. importing of cars etc etc all of which could change or be affected in some way,.......all of it is a little worrying
cant say ive heard of anyone applying for the yellow slip in advance of living here... they need quite a few documents now and some of them need to be apostilled (legally verified from your homeland).
just remember once you are registered with a yellow slip you are also obliged to register for tax as well with annual tax returns,,,,
I think the deadline now is november as it was put back - but as things move forward i d like to think there would be no brexit but in reality i think its 50/50 for no deal or a questionable deal with serious impacts and restrictions for UK nationals in EU countries. and of course vice versa... plus as you say under no deal there will be no transition..... and i suspect all bets are off
However putting that aside.. do your research
make sure its what you want first - living like a local and not in holiday mode....doing what you would normally do in UK but here in sunny cyprus manage your expectations - know what it is you want from the experience.. this changes as you get older and they also change from location to location.... rent first for 6-12 months minimum, as things change, areas change, facilities and services change neighbours (renters owners) change give yourself time to assess and re-assess, do not rush into buying ..it could be an expensive mistake .... get to know the island the villages and what they offer for you...and of course what they dont offer you = certain areas have surefire barking dogs issues (peyia for sure) complexes have issues especially the larger ones - then when you are happy consider buying if thats your goal..... dont worry or beat yourself up about making mistakes we all do it - listen to as much advise and as many viewpoints as possible - consider everything ignore nothing do the research then decide and plan and finally have an exit strategy if it doesnt work out the way you thought it would.
Buy if you want, rent if you want - but in both cases do your homework and use reputable recommended sources.... know the difference between "deeds available" and "with deeds"
good luck from me....