I got it :)
it was a bumpy ride but finally everything is working.
First there was this short and another electrical issue.
And then a longer journey to find a pin assignment which works with all devices.
Touch was not possible to get to run clean as use this config, e.g Option touch gp20,gp21 wold not work. Having system spi on gp22,gp23,gp20 doesn't work either.
But no problem, this is working:
PicoMite MMBasic USB RP2350B Edition V6.01.00RC9
OPTION SERIAL CONSOLE COM2,GP8,GP9
OPTION SYSTEM SPI GP2,GP3,GP0
OPTION LCD SPI GP14,GP15,GP12
OPTION SYSTEM I2C GP4,GP5
OPTION FLASH SIZE 16777216
OPTION COLOURCODE ON
OPTION KEYBOARD US, 0, 0, 150, 50
OPTION PICO OFF
OPTION CPUSPEED (KHz) 378000
OPTION LCDPANEL CONSOLE 7,,, 50
OPTION DISPLAY 30, 53
OPTION LCDPANEL ILI9341BUFF, LANDSCAPE,GP16,GP17,GP18,GP19
OPTION LCD BACKLIGHT 50
OPTION TOUCH GP26,GP27
GUI CALIBRATE 0, 3984, 3772, -869, -639
OPTION SDCARD GP10
OPTION KEYBOARD REPEAT 150,50
OPTION AUDIO GP6,GP7', ON PWM CHANNEL 3
OPTION RTC AUTO ENABLE
OPTION DEFAULT FONT 7, 1
OPTION PSRAM PIN GP47
