According to me u can go solo.. But it not worth it that much.... Beacause mussorie is that destination where various types of activities r there like river rafting, bike riding, paragliding and many more and with friends u can enjoy these activities by 100 percent
Yes offcourse its a good place to visit and if u like snow n all u can go in winters you wl have more fun there.... and solo trips are way better to find your own self.
Absolutely yes...but make sure that the place is not over crowded cos it was shown in news that places in Himachal are witnessing traffic for almost about a day getting stuck in d jam