Their is no casting vote each vote carries the same entitlement in committee. If a committee decision is 3 votes all the motion is lost and it doesn’t matter how the Chair voted
The committee cannot remove the SM only the OC can do that by a simple majority vote.
You need 25% of owners to request an EGM so if you can get 25% of owners to sign a simple request for an EGM it must happen.
Once you have 25% of owners submit 2 motions to remove current SM and replace with your choice of SM with the EGM request or wait until AGM and submit said motion then.