Debranding and unlocking Tchibo stick - Potential Problems?

[RobF]

I own a Tchibo "Internet Stick" with the Huawei E173u-1 modem and Tchibo's modified MobilePartner software installed on the stick. It's possible that Tchibo's customized MP program or something else in the custom firmware of the stick has given me problems with permanently(?) lost Internet connectivity when I used the stick in multiple computers in WinXP as well as in Linux. I'm thinking I may be less likely to run into such problems again if I debrand and unlock this stick.

My questions:

1. How likely is it that Tchibo/O2 would reject the stick after I debrand it by flashing the firmware with Huawei's original Mobile Partner software? Also, where can I find the noncustomized Huawei MP software and flash program?

2. How likely is it that Tchibo/O2 would reject the stick after I unlock it (e.g. with a Lidl SIM-card in place) and then want to use it again with the original Tchibo SIM-card?

In other words, are the debranding and unlocking operations completely safe?

[inquisitor]

Your operator can neither see what software you're using for dial up nor can he detect that your stick has been unlocked.
There's absolutely no technical risk with debranding and unlocking. However the Tchibo-specific plugin for credit management ("Guthabenverwaltung") in Tchibo's version of Mobile Partner do not exist in the original unbranded Mobile Partner. Instead you will need to enter the USSD requests (codes like *101#) manually in the USSD plugin (see Germany - Tchibo - Prepaid Wireless Internet Access for all codes).

[RobF]

OK. Many thanks!