Looks like I have ongoing problem with saddles and you have ongoing problem with your bike, isn't it frustrating ? The fact that you are saying that you can't let go off your handlebars to signal might be because you are either putting too much weight on your front wheel or not putting enough weight. Did they adjust fitting after they put new fork ? Could it be just not being used to the bike? I know when I got my new bike which is half as light as my old one, it took couple of rides to be able let go off the bars because I was not used to bike being so light. Another thing, if it is so bad that it's not comfortable to ride, maybe you should consider selling it and buying something else? I know it will be pain in the ... umm you know what, but in the end you will feel better. I hope you solve it soon