"Could all this selling of stock by Liberty be them building cash needed for a Backup plan to proceed with Hay Mountain intiallly, if JV disussions don't meet expectations?"

No! The company is record as being against the idea, but there is another reason too. At current share prices they can't even come close to selling enough shares to do that out of what is left of authorized share issuance. ...and why would they risk merely starting the program, while gambling that a partner will come in later? Better to have the partner first.