Safe, Probably not.
Somthing else that could be wrong with that set-up is I don't know if the projector is made to be run at that much of an angle or tilt.
Could make parts with bearing wear out faster and fail, like the color wheel and fans.
Maybe someone can chime in on this.
If you need the projector up high shouldn't you turn it upside down like you would do for a ceiling mount install ? That way you would not have to tilt it like that because of the projectors off set ?
What Make model is the projector ?
The color wheel could shatter which could in turn brake the lamp and that could light your stack of AC/DC t-shirts on fire...which would put you on a "Highway to Hell"...LOL..It might be safer to prop that projector up with snowballs