Thinking about getting a flex flail rage 3.5 for my first kite .. is this a good kite?

If you mean Flexifoil Rage 3.5, it's a great kite with quite a strong following. Possibly a bit large for a first kite but that depends more on you, your intentions and the conditions you normally have to fly in.

Tell us more about you and the conditions you fly in if you'd like to get a genuine opinion of your choice..It's also helpful to know what your goals for flying are, Buggying, Static etc...

Im 160 lbs. I would like to buggy and or land board.. I live in st louis missouri

Then the Rage you've picked would be good to learn on. It is not "a trainer" so...Please respect that it can and will surprise you during the learning process and start with very light winds until you have learn every aspect of flying that kite Then start considering the buggy
The 3.5 Rage is a good kite for your buggy quiver long term.

I'm not a landboarder at the moment but I'm under the impression that they tend to prefer depower or at least bar controlled kites for that aspect of the sport. I'm sure others will chime in on that aspect.

Good choice.

A reasonable amount of respect will be required while you become master of the kite . It will be enough power to get riding in a buggy with a decent wind. Plenty of power for scudding . It will work for learning mountain board but I found learning on a board a bit easier with more kite and less wind.

Get ahold of that kite and learn to fly it blind. By then you will have a better idea of what direction you will want to go as far as your next kite and choice of ride. Locations and such will dictate if you get the most out of a buggy or board.

That is a great kite!!! Good allarounder in my opinion.
Love mine.

Great kite to start out with. My quiver is mostly Flexifoil and my two Rages are the 2.5M and 4.7M. The 4.7M gets a lot of use and is a great all arounder just like the 3.5M. The only reason I don't have a 3.5M Rage is because I already had that size covered with another brand.

Do what the others have suggested and fly the heck out of it until you can fly it blind. Start out cautiously and work your way up to higher winds. Winds around 8-10mph should be about right for you starting out. In the link below Angus Campbell spells out all you need to know for where you are right now.
http://www.coastalwindsports.com/ChoosingAKite.html

Awesome thanks to all of you that responded. Im guessing its better to start with handles but should I also look into getting a bar. If so what kind if not why

You get much better individual brake control with handles. Going to a bar after you have mastered handles is sort of a step backwards. Some folks like using a bar for 1 handed flying etc. but you give up a lot of fine control .

The only bar I would recommend is the Ozone Turbo Bar. It still lets you keep most, if not all, brake control of a kite. I love love love my Turbo Bar. I would recommend sticking with the handles for quite a while first though. You will get a better understanding of how each line affects the kite. That way, if you ever do decide to get a bar, you will get the most out of it because bars definitely do limit your flight envelope a bit; some more than others.