1/ My understanding is that any crosswind will act as a critical engine (adverse yaw), Vmcg is only valide with NO cross wind. With 25 Kt cross wind I will not have enough rudder to keep the aircraft on the runway if I have an engine failure at or above V1 Am I correct?
Not really, the point where you will have a problem is if the V1=V1MCG, if the engine failure is any faster than V1MCG the aerodynamic forces on the rudder will have increased so it is “hoped” that you wont go off the side of the runway…… no guarantees though!
2/ The B752 landing gear is 24 feet wide. on a 98 feet wide runway, 30 feet of drift (at Vmcg) will only give 7 feet of runway on the side (assuming no cross wind and immediat rudder correction) am I right?
Remember that the 30 feet is the maximum as demonstrated by an “average” pilot, you might not need all of it.
I would suggest that you get your company to supply you with the V1min / V1Balance / V1 Max for this runway, this would then give you the option on windy days of increasing the V1 beyond V1MCG.
Good Luck.
Mutt.