Can I alter this circuit?
By convention the relay is drawn in the de-energized state. I agree with your logic that you want to reverse the output if your relay is normally open and you have no use for the dummy load (presumably that's there for wind generators that can get themselves into trouble without a load to brake them in high wind conditions). 

Removing Q1, and R5 &amp; R6 and connecting the gate of Q2 through R7 directly to the 555 should work fine, assuming that Q2 is a logic-level drive MOSFET, and the 555 is a CMOS type. 

Unfortunately, neither of those appears to be true- the IRF540 is not guaranteed to work well with (even) a 5V input, and a regular bipolar 555 will have a significant (1.5V to 1V) drop from the LED current, so it will be a marginal mess as shown. 



Suggest you swap out the MOSFET for one guaranteed to work at 3.3V in (or 4.5V and use a CMOS 555).