I think the events surrounding the Maoist insurgency have more or less faded. The BBC has an excellent timeline that outlines the state of the situation:
The situation could always deterioriate once again, as it did in Sri Lanka a few years ago, but that's often the risk in these places. almost 10 years ago
The Maoist rebellion is strictly restricted to the Tibetan/China border and so does not affect Nepal as such. Nepal is pretty peaceful although mild demonstration for the liberation of Tibet occurs now and then but mainly restricted to just sit-down protests, nothing violent.
As to snakes, do not worry unless you are trekking in the hilly jungles. Even then, snakes avoid all human intrusion unless you are so fortunate as to step on one! As you will be wearing thick jungle boots for trekking, snake bite is pretty remote. Not to worry.
What you really need to avoid is refusing alms to those poor beggars around monasteries and temples around town. These people are really really desperate and destitute. A few Nepalese Rupees will feed them forva whole day. (50 NPR is only US$1/-) give as many of them as you can afford. It really means going hungry or having a full stomach for them about 9 years ago
What to avoid?
That has to be the tap water in Nepal as it is not processed. Best is to get bottled water or boiled water.
Avoid the back alleys and byways if you can as sanitation is far from satisfactory in this country. The rivers are filthy and stinks, so be warned.
Street peddlers may harass you for a sale, but if you can put up with it with a kind "no" and mean it, they will leave you alone, but you will be confronted with others as you traverse their streets.
Shopkeepers are generally fair in their pricing but you may meet with a few mercenary individuals and these are best avoided if you can.
Beware of dog poop when you walk along the streets, especially at night as the feral dog population is not kept in abeyance there.
Generally the food served in restaurants and cafe are clean, but beware of street hawker food unless you have a strong stomach else you can have the runs. Flies are aplenty, so do be careful where you eat.
Beggars are aplenty especially around stupas, temples and tourist spots. Spare them a few rupees if you can, especially to those that look really famished and lean. There are those who look well fed but will try their luck with generous tourists.
Have a pocketful of sweets to give to those poor street urchins there. One sweet to them is like a major treat to us. You will be rewarded with genuine toothy smiles from them.
Although Nepal is relatively crime free, it is still best to be on your guard against any suspicious characters lurking around. You can never tell if the clean shaven gentleman eyeing your expensive camera or video recorder is going to run off with it in an instant.
All said and done, Nepal is a beautiful country, relatively speaking. It's people are friendly and courteous and as religion is their main occupation, you can have an enjoyable time there, but still caution is required as in any country, bad hats do exist. about 9 years ago
Oh yes, do not wear shorts when visiting temples, no bare legs while walking in the streets, no overly exposed cleavages, sexy see-through clothing etc. As this is a predominantly religious country, do respect their culture and tradition. Fortunately, the natives are fairly tolerant of the foibles of tourist in their dressing, it would not be asking too much to adhere to the above recommendation so as not to offend the strict code sense of the elders of the community.
Have a pleasant journey in the Valley of the Gods and most importantly, 'hang loose!' about 9 years ago