I recently ordered new arrows 1 inch shorter (by accident) than the previous arrows. So my questions is will the shorter arrows require me to have resight? will I still be able to shoot 125gr tips or should i drop down to 100gr.

You are only talking like 10 grains max buy losing and inch. Question is will they still work with your rest/setup? If I cut an inch off of mine my broadhead would prob touch my rest.

Shoot them and see. Chances atr they will be just fine. Like "DuckButter" said only 10grains difference max.