Can i use nkpatcher with a modchip (X2)? The modchip is lacking some nice features...

Flash the right retail BIOS for your Xbox to one of the banks, lock the HDD with the EEPROM of the Xbox and put the right files (exploit, fonts, NKPatcher...) on the C-drive.

Alternatively: make a switch to turn your chip on/off and which also switches between the HDD (unlocked, all your files) of your chip and another HDD (locked and exploited) for the softmod.

Is it possible to run nkpatcher (without harm) in the dashboard for testing if it (successfully) runs with the x2 flash? Or will it fail for sure?

no harm in testing (worst case it will lockup)
it will work with some OLD first gen BIOS

also use NKPatcher11_U02 with the clock check off....(for now)
you will be able to have full features with alt dash

You can replace the kernel with retail bfm for loading nkpatcher, just have an Ndure/nkpatcher setup on c:

Note... I made my own bfm retails from the retails bios's at xbins, I never bothered using the ready made bfm ones available at xbins.. primarily because my first test machine was a 5838 and there wasn't one available.

Also remember to set the RC4 key in PBL Metoo loader (the standard debug one won't work) and the unhash the correct eeprom key according to you're xbox version in the cfg file.

Again ..also remember to have you're HDD locked.

X2->BFM/Retail->NKPatcher
Nice in theory. But doesn't BFM eat up some memory so incompatibilities/side effects are possible?
On the other hand i have to open the case again and strip one wire to disable the modchip (on the bottom of the PCB i think, dont know exactly anymore...).

What is that 'clock check' for? To prevent the 'clock loop' problem? I thought Ernie&Bert were clean these days/don't touch the clock...

no it overwrites it
and if you are making a BFM point it's boot path to somthing other then xboxdash.xbe
and rename the softmod xboxdash.xbe (the update.xbe) to it
then you can have a softmod thats independent from "chip off for xbox live"

new feature of NKPatcher; if the clock was reset by the fonts (Ernie&Bert)
it will run the msdash with parameters to go straight to the clock setting screen
but if there is something wrong with the msdash support files it will hang...
the fix is on it's way, thats why "for now"

yes.....

Is it intended to prevent users getting in trouble (clock loop, hang) or just a cosmetic issue?

Indeed kind of powerful feature atm. If you disable 'VirtualC' by 'config.bin' you can dig your own grave (if not manually or automatically disabled).

it is for people that leave there xbox unplugged most of the time and were complaining about
all the steps required to get to the clock settings menu
(some games need the correct time set to load there gamesaves)

for advanced users........