you can always re-pitch the wort on a bed of yeast it a sure fire way to get the fermentation process over with. just use the same or complimenting strain of yeast..
as far as fermentation, its up to the yeast. final gravity can be tested or just wait for the air lock to tell you... with all the dry hopping you wont lose any nose if you let it sit...
four day primary? thats pretty bold .. like babe ruth calling his hr... fermenting beer has its own internal clock... if it were my beer i would add more hops at 30min your adding a lot of aroma hops and leaving out the bitter hop addition.
just did a 10 gallon all grain batch... 27 lbs of grain... mash with 8.63 gallons of water ... filled it to the brim,used 10 gallon coach shower type... lol... sparged with 11.5 gallons. as long as your mash water and grains fit's your good.