is it okay to spray self-etching primer on an unpainted(sanded)fiberglass scoop as a pre-coat before applying a high build acrylic primer? thanks.also,how about spraying it over finish-sanded polyester filler putty as a pre-coat before the high build primer? thanks a heap!

NO... etch CAN NOT be applied over fiberglass.

Yes...etch CAN be applied over body filler and poly putty.

Since etch primers are primarily intended for use on bare metal, it isn't necessary to use it on fiberglas; however, it is OK to do so.
Etch primer spec sheets for Dupont, Martin Senor and others specifically state that it can be used over fiberglas.

You should always read the instructions on the can or spec sheet. Some etch primers cannot be used over body fillers or old paints.

Again, always read the instructions/spec sheets.