I love Valheim. I have only one major suggestion, and it involves the quantity of spam-clicking that is involved in playing the game.
There are a few actions that, after a couple hundred hours, you end up doing thousands of times. Most of them are done in quick, repetitive succession, and after some time, my hand has started to hurt from them. I have not modded any of the content of the game, but these specific parts of the game, I have installed mods to alleviate my own physical pain. I offer them in order of their priority to me personally.
Smelter and kiln loading. It takes 25 button presses to load a kiln, 30 button presses to load a smelter, and these 55 actions are performed once per smelter-kiln setup per five minutes (or even more often than that). The game does have an option to press and hold to load items — but it loads them one at a time, at a very slow rate. The time penalty here is massive, making it take almost a minute to load each smelter-and-kiln, and it is time spent holding a button and waiting. Suggestion: the shift key should let you load as many ore, coal, and wood as you are currently carrying at once. It may also be good to expand the hitbox on the smelter and kiln, so alignment is not as difficult, but on this one I'm less certain.
The workbench and forge each require you to spam click the repair button whenever you want to repair your items. This is something I do after every trip abroad. It is quite a lot of spam clicking that is not strictly required. Suggestion: providing an option (maybe in settings?) to automatically repair any equipment that can be repaired at a workbench or forge every time you use them would alleviate this problem.
Mining and tree chopping require you to click once for each hit. If you're taking out several full copper deposits, or farming trees, this is quite a lot of clicks without any other motion, especially early game when breaking a copper deposit node can take more than a few hits. Suggestion: provide an option that lets me hold down the attack button to attack continuously.
This one is less prominent, but the finicky motion required to align crops when farming is also painful. Planting many crops at once is also painful, but to a lesser extent. To this, I only look to the FarmGrid mod: https://www.nexusmods.com/valheim/mods/449. It automatically aligns each crop, so you don't have to jog your character back and forth into place in order to plant many rows of crops.
I think these gameplay changes are very mild, and would only serve to alleviate the physical pain of clicking or button mashing over & over.
Please let me know your thoughts — and if there are any other RSI pain points I may have missed.