Splicing load side of GFCI receptacle
Yes. That's what pigtails are for. No problem at all.

Incoming (from panel) wires -&gt; LINE side of GFCI
Outgoing wires - short pigtails (colors matching the outgoing wires, normally black &amp; white) -&gt; LOAD side of GFCI
On the other end of each pigtail, wire nut the two matching wires to the other locations.

All grounds (both sides) are connected together.