im not sure if you`ve sorted your pyramid yet but here is my 2 pence.
as already stated,your baileys is def the problem no chance of tempering with that mixed in.
best bet get moulds,metal ones or plastic i got metal ones from an online site in the US cpl of bucks,cost a fortune here. temper your chocolate dip the mould in for the outside or fill the inside to the top then pour out,if u dont have thick enough coverage do it again till you do.your mould metal will need to be about 25 c and plastic 20 c . make sure that u put the mould in the fridge for 5 -10 mins then out,if u put it in colder temps than say 10 c u may get thermal shock and the choc moulds may have undesirable streaks etc.
your tempering technique/method can u tell me if u r measuring the actual temperature of the chocolate which is upmost important in tempering getting to the desired high temp to dissolve all the cocoa butter crystals then drop where some crystals set then gently raising the temp to a workin temp so that seed crystals remain crystallised.to close the pyramid i would trace the bottom shape,make cardboard cut out.temper choc put it on acetate or grease proof,wee spread lift the paper up bang it down so there is even coverage cut the shape out b4 setting.
first post hope it helps .