Can a steam gifter be a trader as well?

Not sure I'm following you. As long as you're not trading away gifts you've won on steam gifts, no one will bother you.

As long as your giving away gifts and not taking any kind of games won and trading those then its perfectly fine to be involved in both.

You are not making sense.

the "value" of coupons vs. games is completely subjectional there is no true ratio it just depends on who is trading and how much they value one over the other

that said - you certainly wouldn't expect to trade a 75% Snuggle Truck for Skyrim
but if someone has a good game but really REALLY want a specific coupon for a game they want more they're likely to swap even-up

generally I've seen that most traders expect (and usually get) 3 or more coupons for a medium value game but you just never know

no because if the person saves $25, and your assking for a $25 game theres no point in trading cuz he doesnt save at all.

coupons aren't worth much, anything that saves you $20+ could possible get you a $5-$10 if lucky.

coupons for games on daily deals are worth more since it takes of another percentage of the price. ppl usually give cheap games for those or game keys

Trading isn't that complicated. If you and the one you are trading are both happy with what you're getting from the trade everything is good.