Hello and welcome
I believe the most problems occur with the 1.9dci engine so you might be better going for a 2.0 or 2.2! Don't quote me though, just going by what I've read on here and 1.9dci is plastered everywhere but I cannot picture many 2.0/2.2 engine related problems
Most Renaults suffer from electrical issues more than mechanical failures, it's just something none of the French manufacturers appear to be able to get right 100% of the time! It's normally a case of you either pick a bad one and have every electrical gremiln under the sun or you pick agood one and never have a problem...most like many a different marque of car for different reasons
If you opt for one that has the key card (not sure when they were introduced) make sure you buy one that has a spare key card in working order as these are also prone to failure and cost around £200 to replace I believe so if you've got a spare and one breaks you'll have a bit of time to save up for another
Above all, as you mentioned, a higher mileage with full service history (or at the very least and extensive history) will hopefully have had any major gremlins rectified already. But as I always say, ensure you take any prospective purchase for a decently long test drive and listen to every single noise, check everything on the dash works as it should, remember things like air bag warning lights,
lights, CEL's etc should come on with the ignition, if they don't walk away as a removed bulb maybe hiding a fault!
If you can afford a few extra quid then get either a reputable mechanic or the AA to give the car the once over! Remember, any serious seller will allow for the highest possibly scrutiny if the have nothing to hide! Good luck in your search