I would make room for the assault termies(maybe in a landraider) to run with Vulkan. I know he gives value just being the list but he can easily be instant killed.
I find one hard
cc unit is needed for larger lists.
If the librarian also had termy armour he would people to roll with.
I like the mix of guns all together. So I like the typhoons and attack bikes. However if you are giving heavy armour to shoot at you do not want targets who will then be the target for all the antiinfantry guns, especially the short range of
MM attack bikes. This is tricky as the list seems nicely balanced otherwise.
Maybe given the suicide nature of the bikes a good replacement would be drop pod
MM dreads or even 10 men sternguard with combimeltas in a drop pod.
I know it a balance between ability to do a role to maximising roles. I would favour melta, combimelta or flamer+combiflamer so they when they need to fulfil their role they can do it well. I would give them
cc weapons as they may need them. Sometimes melta than charge in with
PF is needed and sometimes flamer+pistols then powerweapon is needed.
Overall I would be happy

.