Micra 1.0 2003 tickover

I bought this car for my daughter about 3 months ago, becuase there was no tax or insurance on the car the seller delivered it. I have taken it to the bottom of his street and it seemed ok.It then took me a week to arrange insurance before we could drive it.
When we did drive it, it was very sluggish and difficult to start.
I looked on the internet sights and got very frightened at some of the suggestions, fro cam sensor, crank sensor, throttle sensor, air filter throttle body, timing chain, etc etc etc. I took it to my local very small garage who has been in business on his own for 40 years. He explained that it could take some time to finally discover what was causing the problem, he does not have a diagnostic facility.
He decided that it could be due to someone not topping the oil level up and the timing chain hydrolic tensioner becoming slack and the timing chain jumping a couple of teeth.
He was in fact correct, he has reset the timing and once started the car runs beautifully, other than on tickover when up to temperature and stopping at traffic lights, junctions the revs flutter down then up then down and will sometimes cut out.My daughter is a new driver and a little anxious about it.Any knowledgable help would be gratefully received,, thank you
----- Original Message -----
there is little chance of it jumping teeth then still running, more likely the chain is stretched, if it had jumped 2 teeth the engine light would be on constantly due to the amount the timing would be out, check how far out the tensioner is on the chain before doing anything else, when the chain stretches it would give the apearance of being a tooth out :(