Feel free to work towards replacing the Mille Martaux and Bringer's rifle with a pair of Yas9000 with Charge and Demon special.
Also, a simple 50h hell rifle from the quest The Restless Lion would be a good enough hell weapon.
You'd do well to carry a more damaging melee weapon as well.
Sil Dragon Slayer, Excal or Hundred Souls or Ultima Reaper will do against lizards in episode 4 for example.
For single target enemies however, I'd go with something with a bit more base ATP like one of the exclusive weapons that naturally just have high ATP like Blood Tornado.
As mentioned above, a Red Ring would help you. But I'd keep an Anti-Dark Ring on you as well until you can find a SonicTeam Armor during the November event.
Wedding Dress is a good armor for RAcast, but the level requirement is quite high. 192. Best of luck and fun to you.