ProAc Response 1SC with ARC 150.2 Issue

The ProAc's are rated at 100 watts max handling power and the ARC puts out 150 watts. How big a problem is this?

On occasion I'll turn things up loud and I just bought a Rel Strata sub.

Also I've lost the connector for the two sets of speaker terminals. Any suggestions on connecting the speaker terminals?

Thank you.
You can never have too much wattage for speakers, just the reverse. Use some wire stripped bare at the ends.
Clean undistorted power even in excess is much better than less power that's distorted. Distortion is what causes clipping in most cases.
The 150.2 has a built in clipping mechanism, that will shut the amp down when it reaches dangerous cilpping levels.