Well if I read correctly you sid you could only spin 3s off bigger jumps. Well thats fine, hucking isnt cool. To spin smooth threes you will NEED a biggish jump like 25 feet+. What you do is instead fo winding up at all you just approach the jump and as you pop you just look over your shoulder a bit, your arms dont do anything at all and then your head will easily be enough to set your spin, then you just keep looking and if you dont have to move your body at all to set except your head, then you can keep it really smooth and add grabs no problem. The trick to adding grabs is to not be doing a pnecil 3 and then try and touch your skis for an instant, Everything has to be more in control. You have to ste hte spin and then since you are in a nice comfortable position cause you only set with your head you just reach down and tuck up and you should get the grab in smoothly. Dont do any hand movements or leg movements, they are unnesacry, just keep it in control and everything should be smooth. The onyl thing you need to spin and keep spinning is hour head looking for your landing.
As for 5s, find a Jump your comofrtable doing somoth 3s over that you dont need to huck at all. Then throw your spin harder (afterwards you wont feel like your hucking or throwing very hard, but the first few times you should try and throw hard with your arms and all, but still in control) and the main thing to remember is that you need to NOT spot at 360, you have to keep looking over your shoulder till you are around switch again, thats the main thing, DONT SPOT AT THREE, keep looking. Afterwards you will easily learn to put safetys in and throw a smooth 5 just like a smooth 3. Hope I helped.
-Michael Lifshitz-