What am i missing that will make a great detail game look very professional
Content, gameplay... Textures, models, sound fx and music. Those are hard to find for free, or at least the style won't be consistent - and your game will be far from Triple-A game look.
Also your list is missing shadow system, and only good Blitz3D system for that is Sswifts, and it's not free. I'd (and did) invest also for somekind of resource protection like molebox (not free either). And if you need lightmaps and such for your levels you probably want to check out Gile[s] which was made with Blitz.
IMO you need to invest little money to get the best Blitz tools and add-ons, free stuff is usually good enough for most cases but for best results you usually need something that has a price tag.