just an FYI as I have this same model.......if you set the brake and put it in neutral, you can get off the machine while it is running without it shutting off.
I hear some brief noises as well if I'm not mistaken after putting it into forward or reverse and letting the clutch out, it could just be the belt's or pully's engaging or that's what it seem's like to me at least. I haven't heard any lasting noises other than that though. I'm no professional or expert though, these are just my experiences and humble opinion. I hope this help's. Thank you for watching and commenting, it is appreciated.
I know what you mean, I've been using ours and had the hood jar around from time to time. Not sure why they didn't design it to be more secure but I haven't really been able to find a fix myself, you might try tying it down through one of the vent's or opening's in the hood which I've thought about myself but what I normally do is just keep it in first or second gear and take it slow taking my time and for the most part it's fine. It can still rattle around from time to time but it won't go flying up or anything at least it hasn't for me. I hope this helps, just sorry that I couldn't be of more help. Thank you for watching and commenting. It is appreciated.