[thejeff]

With 250% gold and resources? That means you can hire more Vessels. You might want to bump dominion higher, because even at 60g each you'll be hitting that limit quickly.
I haven't played much with indy strength 8, but I'd expect with maybe a little picking of targets you could be sending out an expansion party every turn. 7-8 double bless AVs should rip through almost anything.

If you're only taking 1-2 provinces per 3 turns with double bless sacreds, you're doing something wrong. The Wyrm gets you a province per turn, unless he gets killed or crippled. A double bless should get you close to a province per turn per turn. Your limit is likely to be terrain and chokepoints.