How many moles is it safe to have removed at one time?

I have a number of large moles on my back (around 7), which are raised and large; 2 on my chest and 1 on my thigh. I have consulted a plastic surgeon who has agreed to remove them, through excision, but was wondering if it's safe to have so many removed at once (in terms of infection and pain)? In addition, as the majority are on my back, will having the moles removed lead to a feel of tightness?