Was my arrest legal in this case?

Location: South Carolina

So I (19yo) was going on a roadtrip with my boyfriend from Virginia Beach where we both live to Charleston, South Carolina.

I was pulled over by a cop and he told me I have a warrant for my arrest (for a speeding ticket in SC I forgot to pay last year) he handcuffed me, took me to the county jail where I was strip searched, forced to wear a uniform and was locked in a cell overnight. I was arrested at like 6pm and didn't see a judge until the next morning after which I was released on a bond and I took care of the ticket.

My questions are:

1. Why was I handcuffed behind my back when I am not violent or fleeing I was 100% cooperative?

2. Why was I arrested and not just offered to pay the ticket then and there?

3. Why was I held in jail overnight? Why couldn't I just post a pre-set bond?

4. Was the strip search legal?