Regarding Construct 2 if someone buys Construct 2 from Steam does Construct 2 bought from Steam come with absolutely (unrestrictedly) all exporting possibilities as Construct 2 bought elsewhere?
Yes, the features of C2 Steam version is equivalent with the version bought from the official site. However since I read some users had issues with the Steam version in the past, I'd encourage you to buy it from the official page.
Develop games in your browser. Powerful, performant & highly capable.
Yeah, first rule of thumb: don't buy anything from Steam unless there is no other way to get it. Rule no 2 if you can only get it from Steam, seriously consider if you do actually need it.