Hi Susie,
I assume you know that Labrynth Studios are quite a way out of the village, and with no tavernas close by (as far as I know)? So you will almost certainly need to drive wherever you go.
I am disabled and can't walk far, but we don't hire a car in Crete. Plakias is compact and we stay in the centre. I take my wheelchair (and my ever helpful husband!) to enable us to get a bit further afield. Lesley who has already answered is the expert on Plakias parking.
This site gives useful information about using the Blue Badge outside the UK, which you might find helpful:
http://www.theaa.com/public_affairs/reports/blue_badge_abroad.pdf. On the main road, it may depend on whether the 10 minutes stopping restriction is classed as waiting time or parking time. You can't park where parking is prohibited, but you can where it is time limited, according to the section on Greece. This website also has a little statement in Greek which you can display with your blue badge, if that helps. However, do you really want to go to Rethymno police station to have your ticket annulled when you could be sunbathing or sight seeing?
Enjoy Plakias, I am sure you will.