Only on another character I'm afraid.

Sometimes when i want to fight a boss solo, I sneak up somewhere and wait until everyone has pissed off. Sadly, have other players around is part of playing an MMO. One that I like but it can be annoying sometimes...

Sadly not. There are some repeatable quests in the game (known as daily quests) but generally these are not the main zone or story quests.

Depending what quests you're doing the bosses should normally respawn and let you fight them again, even if the quest has been completed. As ESO is open world you're often going to find other players around you doing the same content, there are some instanced areas which are personal to you and you'll get to fight alone, but for the most part the game is open and this will happen a lot.

Quests which can be done only once have a black arrow above the head of the NPC, repeatable ones have a blue arrow. Story quests are of the first category. Don't feel bad for turning in a quest at low levels if you're on your first character, just leveling to 50. Just enjoy the game as it is. Only some of the quest rewards are useful, and thus worth having at maximum level, but most are bad sets/traits, or simply non-set items.

I don't remember any of the quest enemies being particularly challenging, even on my 1st play-trough when I didn't have any CP. And my build was terrible. If you have problems defeating overland enemies alone, I guess you'll have to take a look at the skills (Are you buffing yourself, using skills that do damage over time?) and gear (Is it at or near your current level and part of your set?) you are using for the respective class, whether you are more stamina and magicka orientated (It's not a good idea spreading attributes around) and whether you have a buff food active (that will add 20-30% to your stats).

It's an MMO, and people aren't "stealing" your quest. There is a mechanism in the game called Cadwell's Silver and Gold, this is where you see the story from the eyes of the other alliances, they are lvl 200 most likely because this is their second or third trip through Tamriel on the "main" quest. To an extent I understand your position but abandoning quests because other people are doing it as well is maddening to me. If there is one thing that is great about this game is that there are people everywhere. Some far flung area out in the middle of mid tier zone and sure enough, there are a group of people, farming, RPing, questing, skyshard hunting etc. Get used to seeing people, embrace it, there are some quest, I'm looking at you upper Craglorn, that you'll be very pleased someone else happened by.

Saw this thread, and made me think. I’m probabably one of many people out there zooming through quests some days. Skill points are important so people who have a lot of alts move fast sometimes. Most quest zoomers aren’t out to hurt others enjoyment or anything like that.

I know, when I first started I was often happy when somebody fast showed up when I ran out of soulgems, and depleted armor made things difficult. I can see where it could be bad though.

Still wish skill points earned through the zone quests were account wide like colors. Found items (skyshards and lore books) are a fun thing to hunt again but the zone missions are always going to be rushed when done 14 times. I want to create an army of crafters so some zone missions are a must.