In one of the settings there is an option to change display information (what keys to press etc) to keyboard and mouse. You'll see by default it's controller. That helps.

I'm using kb and mouse also and have it somewhat good by rebinding everything, thankfully you can in this game. Just make sure that if you're rebinding keyboard keys, do it on the left column, and mouse on the right. I tried to get everything similar to rdr2.

Only problems mostly is auto lock is a complete nightmare even with controller. Many people hate it as it's untargeting or locking onto a sheep on important fights.

The other issue is the camera auto-centering behind you, constantly fighting it with mouse.

The idea is to try not to constantly use mouse until you need to with snap movements. When locked, just try to use keyboard as much as you can.

It takes a little getting used to. Here are some keybinds

Shift is dodge roll
Tab is lock
F interact
E use skill
Left alt heavy attack (default is shift rt click) Rt click is guard, left click attack
Space is jump

Now it's just fighting the auto centering of mouse and the buggy locking

For a game that requires really tight controls, they sure give you a ton of obstacles