Wow, that is a lot of feedback, thanks for that
And yes, I have thought about removing some mods as well.
But let me go through your mentioned ones..
Damage Indicators: You are right, WAILA kinda does this. Will be removed.
Ars Magica 2: It is one of my favourite mods and soon there will be quests for it. Will probably stay in.
Decocraft: Has some very neat aesthetics, will make it optional.
Description Tags: It was used to add lore to some quest items but I think it can be removed now.
FLORA: This mod was actually user suggested, I was doubtful about it as well. May make some quests regarding to it.
Fluxed Trinkets: It is a rising mod from someone I know and I want it in the pack to bugtest.
Ping: This mod is more than neat for a co-op play, will make it optional.
RPGADVMod: The mod is quite neat, will make it optional.
Statues: Just a small mod, will make it optional.
SMT: This mod has some more than awesome stuff upcoming, will def. stay in.
Tails: Will def. stay in, I love this mod to infinity.
TheKitchenMod: It gives a modular feel to the cooking part of the pack - will stay in.
Tinkers Steelworks: In my opinion a nice alternative to Railcraft's steel production and plays well with TiC.
AdminCommandToolbox/Opis: This mod goes along well with Opis and detect lag and diminish it by, eg, purging chunks.
Bibliowoods: Just a neat addition to Bibliocraft that will stay in.
EiraIRC: It is neat to stay in contact with others in the IRC channel to report bugs or discuss the gameplay. If someone wants it gone, they can disable it
Industrialcraft: I am personally not a fan of it, it was user suggested, will make it optional.
Pneumaticraft: Once again I am not a fan of it, however, many people are. Will stay in.