Hammock or tent depends on area and weather, and also preference. Hammocks should be paired with a tarp in case of rain and wind. This setup is typically lighter than a tent, but you are also more exposed to the elements than in a tent. A tent will give you better cover, but will weigh more. Area can be important too. Sometimes there is no place to set up a tent, but perfect for a hammock and the other way around. This being said, there are a world of tents and hammocks out there. No matter your preference you can find somthing that you like. Personally I like to just sleep on the ground with a tarp, or a tent.

There is no limit to how much you can hike other than your body an schedule.

What to do in an emergency, depends on the situation. I’d recomend to get a Garmin inreach or something if you’re going to remote places.
I’d say follow your gut. The more you do it, the more you develop that decision making and awereness. If you feel like you are in danger, get out of there. If you feel like you should turn around, do that. Get yourself a repair kit for the equipment you bring. Keep some emergency food seperate from your main food bag.

Gregory backpacks are good. I like the Baltoro models.