Hi, I will answer what I think about your questions 🙂
1. I think all slots are random and if they were not then I’m sure authorities would be all over them for fixing stuff.
2. Again this could be related to question 1 as in its random so it means you could still get a decent win on say bells or skulls but there are less of them on a reel as compared to says jacks or queens.
3. I find that most games give bonuses out around 50 to 200 spins but I have seen 1000+ spins before now with no bonus so again it’s random and down to luck.
4. I play to what I can afford to deposit if my play money is 40 – 60 I will start on 30p to 40p stake if I manage to get to around £200 I up it to around 60p – £1 stake.
Just remember to not chase losses and have fun playing as its a very expensive hobby 🙂