Expanding on the great answer of IQAndreas, some more things to add in the matter asked by OP (event damage and out-of-combat damage):
- can your ship only be completely destroyed while in combat?
certainly not only. Your can lose the game by event, O2 loss or fire killing the last/only crew member (note that fire from solar flares counts here!), ship can be destroyed by fire damaging systems (since system destruction causes hull damage) and event damage too, as pointed out by IQAndreas. Also, weapon shots may destroy your ship even when the combat has ended already!
On the fun side, while your attacks won't even scratch enemy after enemy surrender has been accepted, fire (possibly from flares) and asteroids can still destroy enemy vessels even though you already accepted their surrender (no scrap in that case, sorry...)
Also, since this can be usually very troublesome to beginners (at least it was to me when I started with FTL), a short list of "which events/dangers should I avoid when..."
(note that you usually don't have to worry about anything when you have 'blue' options available here - but remember that blue options ain't necessarily good!)
As far as risky but rewarding events go, Single Life Form on Moon usually has good rewards, especially if you're low on crew, but the risk of either hull damage or crew loss can be significant here (although I usually go for it anyway, especially with upgraded Medbay); Zoltan "Great Eye" is also quite good with a low crew death risk - but bear in mind that Clone Bay won't prevent crew loss here.
Note that Clone Bay helps a lot in tough crew situations, but I wouldn't rely on it in case of having only 1 crew member (it doesn't work on some events as pointed out above, without the aug crew can still die if Clone Bay gets disabled/destroyed - and skill drop can be a royal PITA in the long run if you have only a single person on board).
Above info is based mainly on my Hard Advanced FTL playthroughs, but I assume it is correct for any kind of FTL gaming experience.