Can holding the urine for long can cause uti, and can soap burning also cause?

Probably yes: Holding the urine excessively may allow some urine leaking to occur thru the urethra , the opening from the bladder to the skin. Bacteria can then wick into the bladder and cause an infection. Irritation to the urethra from soap and detergent may also allow fluids to leak from bladder and cause infection by the same wicking effect.