Difficulty in a game should never, absolutely never comes to "just don't use this or that if you want challenge". Or "try do finish the game naked if you want some challenge". This is pure bad balancing and gamedesign.
Arrow Spray, as it stands, is way overpowered and completely unbalanced, and even if you want to put multipliers based on a difficulty parameter selected when starting a new game, it still has to be re-balanced.
Powerful spells or abilities aren't a bad thing, but only when they are acquired ingame by either getting a high enough ranking, completing a difficult mission, succeeding at a difficult achievement, etc. Here, we are talking a *beginning* skill, which by its very presence and present balancing, tend to invalidate every other skills except Heals and rezzes.
Skills/spells should not be balanced manually depending on difficulty. This would be terrible game design. They have to all be balanced with each others, and THEN, a difficulty setting would apply modifiers.
Anyway combats are a huge part of D:OS. Explaining you want overpowered spells because you don't like combats in D:OS is like telling you want a "kill everything on screen" as the starting weapon in a FPS. Or a Auto-solve button in a puzzle game. Or a Auto-build-base function in a RTS.
This is no Blizzard game where everything is tailored for casual players, up to the point where you can just pay to get your character to max level. This is a RPG with the ambition to go back to the fundamentals of the RPGs, difficulty being a big part of it.
Sorry, but fights are only hard when you rush your character into the middle of the room wearing a g-string right where they can get butchered. Well fights tend to BE hard, but I'm just trying to explain that using common sense and thinking before acting will get you a long way. Blame the player, not the game, unless somes bugs make the game not enjoyable because they are either too easy ( arrow spray ) or too hard ( badly balanced encounters ).
