We aren't talking about cosmology here. We are talking about the earth-moon classical, celestial mechanics.
As far as cosmology goes: Until someone can do a lot more good math on the "opinions" they will remain speculative just as you say. The state of these ideas is understood to be somewhat (or a lot) speculative. They are not, however, just whatever anyone wants to make up.
My third year math-physics prof used to do "cosmology" for fun. He said that was because no one could prove you wrong. That, however, was a long time ago. Now a lot can be proved wrong. You don't get to make up your own anymore. We know way too much.