There were a lot of deaths and dark things happening. Jellal exists because he felt horrible for killing Sieg. That is proof how much of a softie he is.
I think we read different Mangas then because in Rave Master I did not see anything that you say there is.
Rave Master was more dramatic than that, but it was not dark, on the contrary, Rave is very brilliant because it is the Story of the Path of the Hero that saved the world and saved his girl.
In Rave there were deaths if, but if you look at almost all those who died were villains or PARENTS, or the same as in Fairy Tail, how many characters of young Rave Master died in the Manga? Really none ... those who died in the final battle were suddenly resurrected.
If we enumerate important deaths we would really be short, Sieghart was not a protagonist, was an important recurring, Reyna was a redeemed villain, but it was not really vital, Chiba was the most similar to a father for Haru and died because the plot forced him, The same Gale Glory who was a father too.
In FT also died characters as in Rave and although, good characters died few is not as if nobody had died.
FT is a softer Manga than Rave, but not for that is less than him, Rave and FT are different Mangas and with different histories. That's why I think we have to see them as they are, like different stories.