I posted this somewhere else, but basically, I bought DS and feared having to buy a controller, but after using PCGaming wiki, and my own little fixes. I seriously can not believe why nobody ever came back to tell people that if you resetup everything, there is little to no problem with mouse and keyboard with the game.
I have absolutely NO problems with Dark Souls on keyboard+Mouse after reconfiguring everything and using many fixes and what not. I use DSFix and DSMouseFix. This allowed me to set my graphics resolution properly, and it mounted the R controls to the mouse instead of the keyboard.
Then I used cursorlock to lock my cursor onto just one monitor so it doesn't keep closing my game.
After that, we are almost there. I went into key bindings and reconfigured the menu to ESC and exit to the BACK key. Then I configured the button A(use) to my E key and item to the Q key.
Some small tweaks with mouse sensitivity, utilizing AMD CC to keep the game running at good performance (there is known problem where AMD cards will not run at full power due to the port, utilizing custom profile forces the card to run at full processing)
And the game runs VERY well with keyboard and mouse.
Seriously, if everyone took the hour it took me to set this all up, you wouldn't need the controller.
These controlls are very intuitive and easy to use. They actually feel native. Mouse 5 to block, mouse 4 to parry, middle mouse to target, left mouse to quick, right to heavy. WASD, Q to use item, E to interact. CVRF corespond to the HUD and switching isn't actually that hard.
The only problems are the need to switch from one side of the keyboard to the other sometimes to move menu's or close them.
Follow these guys, and you will have no problems with mouse and keyboard for Dark Souls.
Where to find more in depth instructions? PCGaming Wiki, I took the parts I needed to optomize the game from the wiki, and then did key bindings, edited DSFIX.Ini and GUI options and BOOM.
USe DSFix to setup your graphics, DSMFix to setup your mouse. Use the DSMFIX GUI to remap mouse keys. If you have a 5 buton mouse, you do not need to. Then go into game and map the keys to what I have.
Walk around, play around, and remap CVFR keys if you want, otherwise, this almost feels native.
If you already have a controller, more likely than not, that would be better as this doesn't require full precision that a FPS game may require. But for those without, use these instructions. The game plays like the Wither 2 after you do them.
It seems you need a high DPI gaming mouse for this to work though sadly. I have one but it seems you need one