You can definitely mix finger foods and mush, but then it isn't technically BLW. The principles of BLW mean allowing the child to discover all foods for themselves, so spoon feeding mush doesn't really have any place in the 'pure BLW' approach.
Having said that, we did a bit of both - mostly finger foods but spoon feeding things like porridge and yoghurt (basically because I'm too lazy to do pre-loaded spoons)
I can't believe N can't be anywhere near old enough for weaning yet though? He's still a newborn surely??? 
But seriously, if he is showing all the signs (sitting up unaided, able to put food in mouth, interest in your food, no tongue thrust reflex) and passes the banana test (able to pick up a chunk of banana and gum it) then go for it, but do be prepared for LOTS of mess...