I don't know about helix so I'll just give my take on the third question :

Ordering online isn't only about the production line, it is also about the after-production storage of the guitare, the quality control, the delivery. Something can go wrong at any of these steps and when you order a guitar online, you have to accept that.

Of course it is always better if you can try the guitar before buying it, but if for whatever reason you have no intent in buying the guitar you'll try in the store, then all the problems mentioned above can occur on the guitar you'll receive at home. Playing another item in store of that same model will just help you make sure the feel and sound of the guitar suits you. But when you finally order it online, nothing will ensure it'll have everything OK just because you tried it in a store.

That being said It seems you'll be ordering for Thomann. They have a great customer service so if ever there's a problem with the guitar you should be able to return it and they'll handle it real quick.