Dave is right Shaz... learn the FP first. if you try to go to a CP, especially an esky CP heli... you will find nothing but stress and headaches. as Dave said... the Bee has to be set up properly. sadly, they do not fly right out of the box as the suppliers who sell them claim, and it took great advice and help from people here and elsewhere to finally figure out what that proper setup was. mine now will hover hands free for brief periods and are so stable that it isnt funny! but, as i mentioned above... they are heavily modded with cp3 components.
the d/d tail drive will give you accurate and precise tail control, but the hovering requires work with its balancing and swashplate setup and it is really trial and error. are you using training gear? if not, my advice would be to put a set on while you learn. they will save you quite a bit in broken parts and spent dollars in replacing them.
that stinks about the Rx, but i agree completely. if it came with a missing antenna, it was probably bad from the start. it is things like this that run people off from the hobby, but you have held your ground, so, dont give up as people will do their best to help you. you just had a bit of bad parts luck, and we all experience this, so you are not alone. the truth is Shaz, and i mentioned this in an earlier thread of yours... as long as you can fly this Bee with the 35mhz, fly it. unless you are just absolutely determined to have it as a 2.4ghz, which i dont believe you need to do with this one, (in my opinion), fly the thing as it is.. all this time lost trying to do this could have been put to use in proper setup and hovering practice, which is crucial to getting to actual flight. sure, if you can afford it... get another Bee with the 2.4ghz already in it, but use the one you have as is to start hover training, and that is my advice ;).
with the cp3 battery, it will be a bit larger than the stock one, so you may need to adjust its position to make sure of a proper balance of the Bee... but yes, it will work. if you are not sure how to check its balance... just hold it in the air by using your fingertips (battery in and canopy on)under the flybar and move the battery as needed, pretty simple to do. personally, the larger battery is something you really dont need. the stock battery will be perfect for you while you learn and will give you 6-7 minutes of flight time. and trust me... just learning the Bee... that is more time than you will want at once with it, lol. save future money and use it towards more important things, like some backup parts... but that is your call ;).
the extreme blades are very nice and i have used them before. they will help with stability to some degree.
edit: the things you should keep on hand are parts like this. these are the things that you will be breaking the most and can shut you down for days to weeks if you dont have them on hand and suppliers can go for months with shortages on these parts which could shut you down for extended periods. you can get these from what ever supplier you normally use. this supplier is who i mainly use and is just for reference of the parts. they are out of a few things i see though. while it may seem like a lot, its less that a hundred dollars and will keep you in the air. having the right parts on hand is just part of the hobby. the first six are the most important right now though, but you should eventually aquire as much of it as you can :).
paddle control frame (a couple)http://helidirect.com/esky-paddle-control-outer-frame-hb-fp-v12-p-3598.hdx
center hub (a couple)http://helidirect.com/esky-plastic-center-hub-ek-000190-hb-fp-v12-p-19558.hdx
swashplate (a couple)http://helidirect.com/esky-plastic-swashplate-set-hb-fp-v12-p-3599.hdx
rotorhead set (a couple)http://helidirect.com/esky-rotor-head-set-hb-fp-v12-p-3592.hdx
ring like push rods (a few sets atleast)http://helidirect.com/esky-ring-like-push-rod-hb-fp-v12-p-3594.hdx
servo rod set (a couple sets for the dogbone connectors)http://helidirect.com/esky-pitch-control-link-set-hb-fixed-pitch-v2-p-15776.hdx
main motor (a couple if you can afford them but atleast one)http://helidirect.com/esky-main-motor-w-10t-pinion-honeybee-fp-v1v2-p-19757.hdx
cp3 tail motor (since you have this mod done and atleast one)http://helidirect.com/esky-tail-motor-honey-bee-cp3ctcpx-p-15756.hdx
cp3 tail blade set (atleast a couple of these)http://helidirect.com/esky-plastic-80mm-tail-blade-set-black-hb-cp3ctcpx-p-15781.hdx