I've picked this up again but the last 4 still elude me:
4D shoot a couple of liberals in a row (6) -I-L-R. Looks like tiller ((LL in tier, but shoot?)
11A picture board (5) ----E.
11D patron caught pocketing pool of tips intended for staff (5) I have --O?-C
12D invited to be immoral (--D?). Any ideas please?