Swedish's word order is often described as subject-verb-object (like english) but maybe a more accurate way to put is is "verb second". That means when you begin a sentence with things that aren't the subject (such as enligt honom), the verb takes the second "slot" in the sentence after the initial clause.

You can see this in a few other sentences too, such as...

-"Där är hon!" Literally "there is she!", because där is at the beginning. For regular word order you would say "Hon är där."

-"Idag äter jag." "Today eat I". In contrast to "Jag äter idag."

Usually swedish does this to emphasize a different part of the sentence, like saying I eat TODAY.

This page http://www.thelocal.se/blogs/theswedishteacher/2010/03/17/word-order-part-1/ talks about word order a little more in-depth.

yes and no. both can mean clothing belt, but one (cant remember which) is only for clothing belt, the other is for a belt on a machine, a car belt, etc

See comment above

Yes, it's bad. You can't say according to him is the belt green unless it's a question. In English, you'd say according to him, the belt is green. Otherwise it's a question the way you arranged it. According to him, is the belt green? Note the comma.