toilet seat

Q: I had the urge to go to the restroom (for toilet). Before sitting on the toilet seat I usually check the toilet seat whether there is any thing on it or not (I bent my back while checking). The moment I stood straight, I was confused whether from the toilet or normal discharge that gushed out. It gushed so much (this time I really had the urge to go). It was watery and I am confused whether it was from the toilet or clear discharge and that I put my clothes on the floor. I am not sure whether the impurity touched  floor or not. Should I wash the floor? It happened to me nearly three times. 

Q: I wanted to ask that when doing istinja sometimes the water used whilst washing may go on the toilet seat, either at the back or the front of the toilet seat, these can be splashes to drops of water. Are these pure or impure? Also when tried to wash the seat because of this, the water used to wash it then goes on the floor so does this make the floor impure and is it enough to wipe the floor with a sponge? Please help as I don't want to make the bathroom najis.

Q: I really need some advice on the principle of cleanliness. I use to see water sometimes go underneath the toilet seat and then onto the floor of the toilet. However, before I never realised this and carried on wearing sandals from the toilet to the bathroom, and sometimes walked in the toilet barefoot.

1) Does this mean the toilet floor and bathroom floor are najas because of water being transferred? Also, ever since buying a new toilet seat I have seen that this one doesn't allow water to fall from beneath the toilet seat onto the floor but my brother goes in barefoot and walks into the bathroom like that. When I usually clean the toilet seat I see urine underneath, which most likely means the water on the floor was najas all this time. I don't know if my toilet was mopped before or not, but

2) does this mean najas water has been tread on and transferred by foot everywhere. Also, I wash the sandals every time I see them flipped face downwards on the bathroom floor, even though this can be time consuming. I use to suffer from a lot of waswasa many years ago and pray to never go there again. I really need some clarity on this matter because I worry I might over do cleaning things again. I might be overthinking this because my mum also walks into the bathroom barefoot sometimes and even when the floor is wet, which makes me think I might be losing my mind again, but I don't ask her anything about it Incase she thinks I've lost my mind again.

3) If my family walk barefoot on the bathroom floor and then wear a clean pair of sandals I've washed, do I have to wash them again?

4) Furthermore, do I have to wipe the toilet seat with a dry tissue and then with a wet one every time I find the lid open? Does it matter if someone before me didn't wipe the toilet seat dry after finding the toilet lid open? (Sorry for making it very long) I have owned two hoovers so far, and the old one was used in the bathroom when the floor was wet but I didn't know much about cleanliness back then. With the new one, I don't remember if I've used it on the bathroom floor when it was wet, but I am 100% sure that I've used the shorter top end of it to clean the floor when it was wet. Does this mean the whole Hoover is najas; because I don't remember if I touched other parts of it with wetness on my hand.

5) what should I do to clean the Hoover? Do I just wipe the shorter end of it and leave it at that.

Q: To clean an impure toilet seat, is it sufficient to first clean with wet tissue paper and then wipe with dry tissue or do you have to actually pour water on the seat to make it pure?