I've been using starch for many many years- started sewing clothes way back in the mid 60's...we always starched our fabrics before cutting- it does not mess up your machine at all- nothing to worry about- I have always washed finished items --- quilts after the quilting/binding, clothes after the last seam, button, zipper- what ever finishes the item- just to get rid of any marks I may have made, any oil, soil, starch-what ever from making it in the first place- (clothes often were re-starched after laundering- if they needed it- some tops still get starched/ironed after laundering) and---I've been using good ole' Niagra spray starch for 50+ years- if you like using it- go ahead & use it is my feelings about it.
I've never experienced any negative issue from starching my fabric.