I could. Whether you could? Well that depends on you and the team and the level enemy just like it would for me. In short respec well, play well and help others to help you and eachother and fightpool would be an unnecessity.
He will honor his words; he will definitely carry out his actions. What he promises he will fulfill. He does not care about his bodily self, putting his life and death aside to come forward for another's troubled besiegement. He does not boast about his ability, or shamelessly extol his own virtues. - Sima Qian.
It will be harder, especially as I don't think Fire secondary has much in the way of soft control powers for adding extra damage mitigation? Best way to check may be to pop along to Sirens and Bloody bay to see how you fare against some of the mobs there when you are exemped to 25 and 30. Will give you an idea about how much aggo you can handle at those levels. Pick a quiet time so you don't have to worry about being jumped by any villains. 
thx for replies guys
thx for advice in bloody bay though - didnt think abt that 
I also think that it will be harder, but possible. Prob hav to rethink my "3+ mobs is ok when in granite" - as i think I will be doing well at +1 with lowbie armours
to all the stoners out there - got a question please
; but i dotn think i can bare the lack of offensive powers. Can i surive as a exemped tank on stone arm/stone skin/crystal/minerals with L45/50 SOs if I DONT take the fighting pool powers?
Question: Is stone primaries (ie stone/crystal/min arm) with L45/50 SOs enough defense/resist to function effecetively during exemps? (cos I dont wanna take the fighting pool power)
Reasoning for Question:
after L32 - i repsecced my stone tank. i threw a way all my useless primaries as well as fighting pool. Got loads of fire secondaries - and absolutley love it.
But now the time has come to consdier doing the lower TFs
TY for ur input