Yeah like our brothers in arms we too can cast two powers a turn, but it comes at a hefty premium. Arguably not worth it, unless you build your list around it.
I'd agree with articor on those furiosos, the fragioso is the way to go. My 1850 has something very similar (two of these bad boys in a drop pod kills shit up, let me tell you).
I'd argue that the priest is not worth it in this list, as he can only affect 5 assault marines (DP capacity is 10, so can't join there, and does nothing to DC. And capacity is still 10). Those points could definitely used for, say, another bike and adding meltas to that one (definitely squads of 2-3: I prefer 2, gets the job done, but 3 if you want to be able to soak some fire).
RAS - Eh, they're fine I guess. I don't really like mech personally - anything with av<13 is useless at surviving in my opinion, and these tanks are decently expensive at 55 each. Easy first blood for 1 long shot, 2 at med range, 3 at short (but by then they're already dead). Pretty much the only purpose for this unit is to screen the bikes, as far as I can tell. I would put them in pods, as it's 20 points cheaper and makes this list a bit better (the only people not in pods are in razorbacks or on bikes - what do you think will happen if you don't get t1?) and more unified.
Honestly, how I would run it is this.
Libby, Priest and 8 assault marines with 2 hand flamers (sarge) and a flamer. 10 more assault marines with meltas (optional powerfist, if points). Those tac squads. Those dreads. Them DC. That's 7 units, and if you put them all in pods you have 4 coming in t1. Tanks? Goodbye. Infantry hordes? Interesting. Add in that SR for anti-flier (if meta has lots of av12 fliers I'd switch to LC on him) and you have yourself a list with no one on the table. That's an interesting situation, don't ya think? Go second, he wastes his first turn, you drop in and get first blood (and linebreaker), kill some shit and then get one extra turn to deal out pain and grab objectives. Just an idea, since your list already focuses so heavily on pods (2 av11 tanks 12 models including your warlord and your 2 bikes are all that starts on... not too hard to just lose them all).
If you go down to the woods today, be wary