Singing and dancing on the occasion of nikaah

Q: In 2-3 months I'm getting married. We are Pakistanis so in our culture before the wedding day we do an event called Dholki where people get together and sing and dance. I'm trying to avoid doing haram things. 

Is it possible to use drums at the event? Is it only duff that is permissible? The event will be a female only event. Can we dance? At the nikaah event can we use music with only vocals and drums? 

The number of steps on the mimbar of Nabi (sallallahu alaihi wasallam)

Q: We are building a Masjid and would like to know how many steps did the Mimbar of Nabi (sallallahu alaihi wasallam) have. 

I have read that it had 3 steps in total (including the seat). Nabi (sallallahu alaihi wasallam) sat on the third and stood on the second. 

However, the famous Hadith of Ramadan states to the effect that Nabi (sallallahu alaihi wasallam) ascended three steps and said Aameen on each step, which would imply there were 3 steps excluding the seat, which is 4 steps in total. 

Can you please explain and clarify the above to me.

Keeping track of an insurance company's products and payments

Q: I work as a programmer for a company that has multiple customers like jet, Edgar's, Pep, Hollard, etc. 

Whatever the client requires, we create a program for it. 

One of our biggest systems is to create and maintain a program that allows Hollard to keep track of their customers insurance products and payments. We do not gain an income from the insurance payments but they pay us an admin fee for the use of the system. Is this considered a halaal income?