Meaning of reusing water in wudhu

Q: I’ve heard from someone that it is impermissible to reuse water for wudhu, however if someone lets the water from the tap run over his arm such that only one side of the arm is being directly hit with the water and the other side is getting wet by the water flowing over the arm, then will this be a valid wudhu?

Placing a plaque with a short dua instead of the donor's name on a well

Q: There is great rewards in making sadqah in the form of wells. I wanted to know if on the well it is permissible to have a dua instead of the donors name. There are wells I've contributed towards, but charities insist on a donor's name. My intention was to make Allah pleased so I requested short duas on the plaques instead. So the benefactor remembers blessings. Is this permissible?

Combining salaahs due to illness

Q: Can I combine my prayers? I have a urine condition where if I go to the toilet, then after a few minutes, I feel that there is a drop of urine coming out.

Due to this condition, I try to not go to the toilet in the daytime so that I can perform my prayers, but it is a painful process to suppress your need to relieve yourself.

Can I combine my Zohr and Asr prayers and then perform the Esha prayer with Maghrib?

Selling a stolen phone

Q: I bought a phone to sell from someone but when they came to sell it while I'm paying them they say the phone is on contract and they have a way of wiping the name of the person who took the contract off from the database etc. so they don't have to pay etc.

Afterwards I realized it's like stolen so I messaged the person and told him I want to return it but he's now insisting that the contract will be paid for monthly.

What do I do? I sold the phone now, what do I do with the money from it? Is it halal for me to use or must give it away in charity?