We have a problem with bombs.
There is no reason to use a bomb at the 1* and 2* levels compared to a gun or a sword for a simple reason: DPS. The charge time simply does not allow low level bombs to be a viable alternative to other weapons, and they only really become useful at 4* and 5*. Some people use them for the status effects, but even that relegates them to the position of support weapon, when they really should be a viable main weapon.
So here is my suggestion: A multi-level charge system.
1) Bombs have multiple levels of charge that allows that player to control bomb blast radius. The higher the charge, the higher the radius.
2) It takes more time to build up to higher charges.
3) Bombs will deal the same damage regardless of the charge.
4) Higher tier bombs will have higher charge limits then low tier, and therefore, higher maximum radius. Of course, in addition to higher damage.
I shall now discuss what this means:
Under this system, players have the option to increase their DPS throughput to a lower crowd size as they can spam low level charges on a single monster, or allow the charges to build up to hit a larger crowd size.
This means that high tier bombs can sacrifice their insane blast radius for concentrated bombing against a single target, and lower tier bombs will be able to compete with other weapons in terms of DPS due to limited charge level and therefore low charge time. In fact, under this system you can give a normal attack to the bomb by making the normal attack produce a level 0 charge of the smallest radius blast. This could make it close to a gun at least in terms of DPS. This system would allow bomb users the flexibility to tailor their bombs to the crowd size, and should make for very engrossing tactical play.
Also, let bombers throw their bombs within a maximum range to their cursor. There's no reason those goblins can do it and not knights! Currently you lose all your charge when you get hit, and combined with high charge times at low bomb tiers, it makes bomb usage as hazardous as sword usage with less dps then guns.
Bombs need to change, at very least at lower tiers. Higher tiers could be changed too, to allow for more flexibility.
a multi charge bomb isn't a bad idea the first stage could be really fast while the next stage could be longer
no to the throwing of bombs... gremlins also have healers and OOO said they wont put in. this would be OP for chemical bombs