Yeah, I live near Frankfurt.

I think a space theme could easily work, but I have no idea what kind of gimmick they would use. I have no idea how the switches from Fourze did in sales, but I would assume it would be something completely different

I think the mechas could be like megaranger.

I was thinking more like Timeranger; a bunch of smaller space ships that come together to form a giant space ship/gattai.

I think each Super Sentai series should have a Kamen Rider counterpart for example, Magiranger and Kamen Rider Wizard. I thought there should be an insect themed Sentai to match up with Kamen Rider Kabuto.

A allusion to vehicle voltron ?

^ I don't understand what you are trying to say.

Just using different space ships, like in Timeranger, to create the gattai. Wasn't Voltron all comprised of mecha cats, like panthers or something?
I really don't think we will ever get an insect themed sentai. A pair of extra rangers has worked in Hurricaneger and Go-Busters (although Go-Busters is the new basement dweller in Toei's eyes), but I really don't think Toei and Bandai are going to try to do any encroaching on KR. KR is the money maker and eye catcher, no reason to mess with that.

Wasn't there a second season with a different Voltron that was vehicles? I've never seen Voltron, but I'm told this is the case. It wasn't as popular as the one with the big cats.

There was a vehicle voltron, but it has little relevance to what the others were suggesting.

In Japan he was called Dairugger.

There was Voltron, then the season with two Voltron, one Lions and one vehicles from where the space federation or whatever tried to copy Voltron's powers. Then there were 3 other seasons called Land, Sea, and Sky. Each season Voltron was comprised of vehicles/machines that fit the title.