[Honor 7 Q&A, Help & Troubleshooting] Dishonored7:
First: I've created my answer in a hurry in the afternoon, not seeing that the forum has rejected it due to an external link (apparently one needs to have 10 posts before being allowed to post external links).

Meanwhile I've made some progress: when trying to backup my current (damaged) system before doing additional damage :) using TWRP, it suggested the following filename: PLK-L01C432B380! So I've had the suspicion of being on B380 already, now I'm betting for it. In parallel to this post I'm downloading this firmware from a Polish site (no ext links!) and will extract the boot.img using the Huawei Firmware Extractor as mentioned in one of the posts above. Will keep you updated, but might be tomorrow. Thanks again for your support!!

Update 2: download failed, my internet speed is down => tomorrow

Update 3: this Google Captcha is driving me mad!

Reply from afternoon:

1. Yes maybe, try reinstall HiSuite and change USB if use USB3.0 try to USB2.0

=> Will try this tonight!

2.U have access to twrp, right?

=> yes, volumeUp/power is booting TWRP

3.Not exactly must be all roms in a zip file!

=> would they consist of a single IMG file then or hundreds of individual OS files?

4.Install rom via twrp is good way...so if can enter to recovery...

=> gaining some hope (not expecting getting USB to work)!

5.Is hard to say right now way u can insatll rom via twrp, so after more info

[MENTION=8382644]Dishonored7[/MENTION] So I need to know waht u do how last when your phone works, your version of twrp and your model number (whole)

TWRP: twrp-3.1.1-0-plank.img from their Honor 7 page:

*** no ext link ***

What I'm just seeing there that in the "Install" section it says "Requires TWRP 2.8.4 or higher already installed". Have not looked at this before.

I've got the phone new on Saturday (!), either was customer return (open box) or refurbished by Huawei, looking like new and wiped. UNFORTUNATELY I'VE NOT NOTED DOWN THE BUILT NUMBER (update: see "First" at top :) ). Only checked that it said "Android 6.0". During initial setup of the phone, I've been asked to accept 2 system updates, improving work with contacs and other minor things. Could have been the stuff that came with B390. The B-versioning I've not been understanding until I've seen a build number ending with Bxxx on a screenshot. Model is PLK-L01.

I've been following this (German) instruction, but have downloaded the latest version of TWRP and superSU:

***anleitung-honor-7-root-m-twrp-v2-8-7-0-fuer-plk-l01-b170-t318499

It's 3 steps:

- unlock bootloader using an Huawei unlock code generated for my device

- install TWRP via ADB

- install SuperSU via TWRP

All went fine until rebooting after SuperSU installation. I thought it all was good, doing some notes when looking at the device seeing the rescue screen...

6.For u will be much better to flash stock rom

OK, could it be the most recent version (B390)? Would it be important to flash the same version than I had initially (could guess only)?

Will the bootloader remain unlocked and TWRP installed? I wanted to either install a custom ROM like Yoda coming with xposed already or stay w/ original but install xposed myself.

Regarding your hartbeat: your support is appreciated a lot! My phone is bricked already so not much to loose :) I'm very happy about getting some general information about Android rooting, am very thankful!