You're going to get different feedback from different people. Some will say that they were great, others won't. Use them at your own risk.
Yes, they are legit. Miscommunication is what people believe to make them seem dodgy. However, they are legit.
VERY LEGIT with gold, they may ask for ID, just give it to them...you can just snap a picture of it and send it to them. I have never had a problem with them buying gold. However, they're usually more pricey
They are defiantly more pricy then sythe and have translation problems(can get confused easy). I'd say use them at your own risk and use a credit card which you can dispute charges so if a problem ever does arise. Edit: they verify each order, call you up etc... They might also ask for your ID if you have a big transaction.
For GP they are legit, but they are a bit dodgy with accounts purely because the accounts get recovered so they have to chargeback any payments if you sell to them etc.
Buying RS Gold from Gold4fun is the same thing as buying on a legit and highly trusted seller here on Sythe.
They are trusted in my opinion, but when it comes to things where miscommunication can be an issue, ie buying an account, I wouldn't trust them. The "I don't understand english" excuse is a treat for them in scenarios like that...