I am not familiar with your boat but the baby stay performs two functions. It is used to pull the mid portion of the mast forward which flattens the mainsail. Also if your mast is a fairly flexible section then it may "pump" that is bounce forward and aft in the mid section when you are beating into chop of wave action. The baby stay can be tensioned to eliminate this pumping.
So you can try sailing in these conditions and see if your mast is pumping, if not then you may be able to get a way without a babystay. You can try some backstay tension which will likely pull the mast head backwards which will result in the mid portion bowing forward which may stop any movement.
It is fairly common for sailors to remove their babystay. I have a similar 30 footer an S2 9.1 which has a babystay. As far as I know everyone with one has taken it off the
As to the Yanmar, there are a great engine and I would recomend leaving it in. You should be able to find a folding prop some where.