I am about to pick my monk style but there are a few questions I would like to ask here before I make that choice and then regret it latter on.
I am thinking of going the harmonious route but see from posts here that alot of it is bugged, but the posts are rather old so is it a viable style to pick?

Also if I do pick a style that I latter find I do not like can you change it ?

First, welcome.  The monk is a lot of fun. I offer this warning though: Beware, you are about to get addicted to FD! 

As for the styles, they are all viable.  You may see us complain some here or push for some minor changes, but that happens with any class.

My best advice as to style is try them out and see what you like. I personally settled on the drunken style but I have been tempted from time to time by the harmonious style.  The quest to change styles goes pretty quickly so its not too big an issue.

Sergius of Onslaught

currently harmonious is the most polished and finished of the styles so playing it isnt as much of a chore as playing dragon. 

Dragon - Highs, good dps in groups, but probably about the same as harmonious / drunken at 46+ (atm)
               lows, no mitigation, that only utility youll get is invis/levi and thats at 46., and the more you level the more the other styles catch up in dps, at 50 the offensive stance is only 2 % more dps then drunken, the tank class

Drunken - Great for transfering hate (if its working correctly, a few have mentioned that it might not be adding correctly), supposed to be the most defensive of the monks, but has less defensive buffs then harmonious, and the defensive stance is only 1% better then harmonious monks

Harmonious - more attacks then drunken, fewer then dragon (although dragons extra attacks are ae's and are thus useless to most monks) has a high dmg dot attack (personally too high and should be lowered, or the ending dmg removed so its at least equal to dragons) TONS of debuffs, can reduce ac, str, dmg, of target, can slow target and haste self. 
lows - the offensive stance is rather harsh, but the high crit rate, tons of debuffs, numerous self buffs, and diamond skin more then make up for it

In defense of paladins ive seen lvl 50 pld solo 53 5 dots :-p 
In the same hand as a dragon (while leveling) i never killed a 3 dot higher level then me :-p (thats just one 3 dot)

As someone who plays a Pally and a monk I can say my Pally has had no more difficulty killing than my harmonious monk-admittedly more slowly, but after fighting 2 3dot mobs on my monk I need to let my health regen, meanwhile my Pally can move on to the next fight...of course my pally kills very slowly so even moving straight to the next fight its probably still slower than the monk killing resting and moving to next fight.  Certainly on Skawlra rock against the lizards my Pally was able to take on 3 3 dots with about a 40% chance of living whereas my monk had to FD after killling the first.  As a side note, once in your teens, your pally should never be unable to kill a 3 dot mob solo as long as it is within a lvl or 2 of you.

Also my pally can much more reliably kill a 4 dot mob than my Harm monk can-the monk heavily relies on my counter attack after a parry to decrease the damage, but that only lasts 8 seconds and despite a high parry % its unpredictable-some fights I can barely get a normal attack off as my counter is constantly up and then I can go in a fight and see my counter once throughout the whole fight.

But fighting with the Pally solo is so very boring, whereas monk fighting rocks

I certainly wasn't upset, just wnated to let you know from my experience as a pally that 3 dots should be no issue fighting, so if it is then likely some tactics or gear needs adjusting.  As for a which class is better debate, well I'd be useless in that-I play a Pally War DK Monk and Ranger and while tanks are my favorite clss type, I still can't decide which i think is best