Copyright/licensing confusion

Hi all
I have just stumbled across the sketchup warehouse I saw a few models that I would really like to use in a game I’m trying to make but there is a lot of conflicting info on copyrights.

So basically i been working on this game for close to a year now(solo) and am looking to add more models(medieval settings) for atmosphere. All the 3d stuff i have already is from free sites such as blendswap sharecg etc which have very clear licenses here not so much.Also there seems no way to contact the author/authors.

So the tos on the warehouse seems to state that all models can be commercially used as long as one does not claim they are yours or try sell the model on its own or part of a pack.

As i am using the models as part of a much greater whole am I allowed to use them if my game goes commercial? I have bookmarked the pages of the models i like and will provide the link to the page as well as the author in the credits section.

But… now the only way to open files from the warehouse is using skechup program and that has its own licencing model doesn’t it?. Unless u use the pro version you can not use anything (exported)from the program commercially.

Does this mean that while the models on the warehouse can be used commercially you may not use them commercially unless you have a pro license for the sketchup program lol . Very underhanded and sneaky if this is the case(Im using the trial pro version (1month) to open and export the models from the warehouse atm).

I would just like to know one way or another where i stand before i invest any more time than i already have on the warehouse.

Thank you