Since I do a lot of RCing and buy lots of lipos, let me give a little input.
Lipos are not dangerous is properly cared for. Balance charge every time at 1c (you get the C by dividing the capacity by 1000...a 3500mah lipo would be 3.5c...a 4200mah would be 4.2c...etc). Do not over discharge them. Let them cool before charging. And do NOT store them fully charged. If you really want to extend their life, do a few charge/discharge cycles on your charger before you use them.
C ratings on lipos (the supposed "burst power level", if you will) are often times VERY overrated! You have some companies out there (Looking at you here MaxAmps) who sell batteries with insanely high C ratings (over 100c supposedly). Do they perform better than a 20c lipo? Sure. Better than a 50c pack? That is debatable. I have had some of the 2s 5000mah Turnigy Nano Tech 90c "race packs"...and to be honest, they were not that impressive. I had a set of "budget" $20 5000mah 25c packs that, in my trucks, performed just as well as the 90c.
From reading on an RC forum, there are really only a few plants in the world that MAKE the cells for lipos. So if you pay $30 or $130 you might be getting a cell that came from the same place. There is a good deal of speculation on this, but it is thought that some brands are getting their batteries all from the same place.
With that said, the lipos that are my favorite are the blue Turnigy and Floureons (off eBay). I have a set of blue Turnigy that I bought back in 2015 that still balance charge up to the exact way they did when new, and have IR readings just like new. My Floureons also are very good lipos. I know a guy who tested Floureons, Turnigy HeavyDuty, and GensAce in a RC boat and actually got his highest speed with the Floureons.
As long as you treat them well lipos can last a long time with 0 issues.