Daum is quite unstable and by using it, you are on your own.
Try using a non modified build from: http://www.emucr.com/search/label/DOSBox

ECE version is already installed but i need to emulate CRT features (excluded the curvature) and i don't want vertical borders...

and i'm getting ECHO problems with musics (fluidsynth mode)

well I am not recommending the ECE version in my post. You won't have fluidsynth problems in the linked build as it isn't part of DOSBox.

Ok fixed... with my G402 if i try to use "automatic game detection" option it works bad and jump also with 125MHZ of polling rate; if i try to use "on-board memory" option it works fine when i use 125MHZ of polling rate

i don't know if can works with steelseries model (i don't have tested steelseries software for now) but i think yes

DOSBox-X developer here:

SDL 1.x by default detects mouse motion in capture mode by centering the cursor in the window, then the next time it processes events, measures "movement" by how far the cursor has moved from the center using GetCursorPos().

SDL 1.x expects older Windows behavior where SetCursorPos() has an immediate effect.

Under Windows 10 (and possibly Windows 8?), SetCursorPos() does NOT have an immediate effect. GetCursorPos() will not return the new position until about 1/60th of a second later.

When SDL 1.x is given a chance to process window events too often (in less than 1/60th of a second), it can "see" a lot of sudden mouse movement because of this issue.

The SDL 1.x library in DOSBox-X was modified to enforce a 1/60th of a second interval to prevent this issue.

The stock SDL 1.x library can be modified in the same way to resolve the issue.