Umm no. Power Rangers tends to work on a pretty small budget even now a days. It is doubtful they could afford Whedon now after he's become such a big and well known filmmaker. Maybe back in the early 2000s around Buffy, but now a days, nope.

No. PR is produced on a budget of a couple hundred thousand. Whedon's contracts will probably be asking for multiple millions.
Unless Saban himself steps in and pays for him out of pocket, there is no way any producer can get him.

Who would replace Judd Lynn someday ?

Mudd Jin.
How is anyone supposed to know?

Usually around the middle of November is when the megazord and morpher start to come out. The figures start in December/January.

I could maybe see them getting Whedon to work on a sequel to the new movie. Though I don't know if he's ever worked with Lionsgate before.

Do you guys miss the californian vibe of the show ?

Not at all.

Why ?

Nope. I like variety.

Although pretending New Zealand isn't New Zealand but having episodes later set in New Zealand when it still looks like New Zealand is a little weird.