I like how there are choices for the primary and melee weapon, but I think there could be a few more.

I chose three vanilla terraria weapons I thought could be interesting additions to TerRoguelike and cheated the weapon in to see if they'd be balanced, tweaking the stats if they aren't.

the weapons are as follows:

flamethrower:
decreased damage to 22 per tick (damage dealt was always 1 less than what I set it to, so I had it set to 23 to make it deal 22. 20 felt too low and 25 felt too high, 22 was a middleground), removed knockback.
I chose flamethrower because it would function differently than any of the three weapons in the game as is. It would deal more area of effect damage, but it cannot be used at range and no knockback means it cannot keep enemies back.

molotov:
increased damage to 60, added auto-fire, increased projectile throw speed to 10
I was originally going to choose grenade because of its arc based projectile, but I chose molotov over it because molotov has the same arc, but explodes instantly instead of bouncing or sticking, tosses out fire particles that deal impact damage, and the fire particles landing on the floor linger for a bit and deal damage to enemies that walk over it.
The lower base damage than other weapons, weird arc, and limited range make it somewhat harder to use, but the overall damage output if used correctly is higher.
The reason for the projectile speed increased to 10 is to give it some usable range without making it too easy to use. For example, before I buffed it, the projectile speed was 6.5, and that led to situations where attacking certain enemies in certain scenarios was too clunky. 10 makes its less clunky without being easier.

megashark:
no changes assuming no ammo requirement (The endless musket pouch is not the same as not requiring ammo, as endless musket pouch is musket balls, which add 7 damage to the weapon)
I chose the megashark to be the starter equivalent to the minigun drop item that lowers damage but increases attack speed, similar to how a sniper rifle was added as one of the weapon choices. Megashark deals 25 damage, hits faster, and has bullet spread. It felt like a balanced weapon just as is

weapons I wanted to try but haven't gotten to yet:
piranha gun
those style of magic weapons where the projectile follows the cursor and pierces enemies (there's three of those it doesn't matter which)
shotgun