I have lived most of my life in Leixlip so maybe my answers are a little biased but I will share my thoughts.
- what's the town centre like ?
not great a bit small but it has all the essentials probably the one thing the town lacks is a decent supermarket although there is a Lidl, Supervalue and Eurospar scattered around the town.
- is it safe ?
I would consider it a nice safe town it's not crime free but where is these days.
- are there trackies roaming about ?
yes there are lots of trackies as there are 2 GAA clubs and 3 different Soccer clubs, a Rugby Club, Canoe Club plus the Amenities center which has a Gym and five aside pitches so the sporting facilities are good.

If however your implying 'young guys in a tracksuit = criminals' you might be better off staying in your Ivory Tower where you won't encounter someone in a tracksuit. Sorry but questions like that annoy me.
- anywhere in particular to avoid ?
Most of the housing estates are fine bear in mind if you are looking at the likes of Rinawade or Glen Easton it's a good walk to the bus stop. Your also looking at a taxi cab home after a few beers if your drinking in the town and living in one of those estates. The town is serviced by the nightlinks should you want to go for a night out in the city.
- will my nice car be safe parked in the drive all day ?
Cars get robbed it's life it could happen anywhere but I would be shocked if it was robbed anywhere in Leixlip during the day.
- schools
very good, 2 secondary, 2 primary and an Irish school
pubs
not as good as some towns but lively enough and the Courtyard in the middle of town is a late bar at the weekend
restaurants like ?
This is one thing the town does well, plenty of places to eat in terms of restaurants, pubgrub and takeways. You have Chinese, Indian, Italian etc. the likes of Becketts, Miss Wong's, The Amber Regent are excellent, Da Vinci's isn't bad either.