What is my buggy suppose to be doing in the neutral position on my controller? Right not it will roll away unless I push the controller to the brake position.

It should not move in neutral. I'm guessing that your idle is too high and you need to adjust this. To do this turn the idle screw on the carb (usually the one with the spring on it) an eight of a turn counter clockwise until your buggy does not move at neutral. Hope this solves your problem! [8D]

sound more like to me your trim is incorrectly set on your controller(transmitter)..............

Could be a combination of Both....

A lot of folks seem to have difficulty with the Mechanical linkages and getting the Idle and the Throttle/Brake linkage set up properly.
Then they try to compensate by using radio trims to solve the problems.

I take it you are talking about freewheeling ... might not matter under everybodys circumstances although in some I would say it does , what kind of buggy are you refering to ? some buggys need freewheel and some dont ... if this is what you are talking about then your answere is that everybodies drive/race style is different and some prefer some and some prefer none (freewheel) ... a couple months ago there was a thread with several comments from several people about several types of buggies and styles and so forth ... I freewheel with my buggy and trug and some more technical track set-ups I might have almost no freewheel

Check this 1st.
If your buggy is freewheeling and you don't want it to diagnose the problem in this manner. With engine off and car and radio on take off air filter. give it gas and then release look in the carb if when you release the throttle. Does the slide in the carb return to closed position should be aprox 1mm from completely closed in most carbs. If it does not hit the brakes see if that pushes the slide to the closed position. If it closes after hitting brakes then you need a throttle return spring. i.e. a couple rubberbands around carb and throttle pin should do the trick. The kind you wife or GF uses in there hair will work and are fuel proof. Also work wonders for keeping pressure on fuel tank lids.

If when you hit the brakes the carb only closes to 2mm's or more it's your idle screw turn counter clockwise to close gap. Of course clockwise to open gap. Slide should be held open when adjusting.

Now that you know your basic setup is fine check your radio trim. Adjust trim and watch linkage. Trim should be adjusted so when in neutral there is no servo load from either brakes or throttle. Carb should be closing automaically with addition of rubberbands. make sure your throttle linkage arm has enough length to be in neutral and still close carb. Without applying any load to brakes. Length can be adjusted through the turnbuckle at the end of the arm at servo horn.

Now that you have your second principal taken care of. Make lsn adjustment with car warmed up.