Shimano BB-UN300 bottom bracket, BSA, 68x122.5 mm, square

Hello. While installing a new chain on an older MTB bike, I discovered that the bottom bracket was almost worn out.
I removed it and found that it has exactly this composition (BB UN-300) so I need to order it and replace it. Before ordering, I want to ask two questions:
I found that the left crank is about 5 mm further from the frame than the right. Measured against the right and left frame tubes facing the rear wheel axle. Wouldn't it be better to use a 118 mm axle length?
I don't know if only the length of the left part of the axle changes and the right side remains the same so that the chain line doesn't change.
Unfortunately, the composition did not last long. Is it possible to assume that the FSA BB-7420ST composition will be of better quality?
https://www.mtbiker.sk/shop/komponenty/stredove-zlozenia/zavitove/fsa-bb-7420st-stredova-os-68x118-mm-stvorhran-bez-skrutiek-oem-p234826.html?itm_medium=widget&itm_campaign=#reviews

Thank you

Hello.

Thank you for your response today, April 6, 2025. I looked at the removed bottom bracket and found that it is a D-NL type.
According to what you wrote to me, I should not experiment and should order exactly the same composition.
In the e-shop you only have one D-NL configuration and the dimensions are the same as the one I removed. So I assume the item description applies because the picture shows the LL configuration.
https://www.mtbiker.sk/shop/komponenty/stredove-zlozenia/zavitove/shimano-tourney-bb-un300-stredove-zlozenie-68x1225-mm-d-nl-bsa-stvorhran-mtb-p110093.html?itm_medium=shop&itm_campaign=personal-product-recommendation#reviews
The reviews for this composition are not good, but is there anything else I can do?
Thank you

Dobrý deň.
Chcel by som sa opýtať či je možné na toto zloženie použiť túto kľuku: https://www.mtbiker.sk/shop/komponenty/kluky-a-prevodniky/mtb/2-prevodnik/shimano-stred-altus-mt101-175mm-36-22z-9-k-cierny-bez-krytu-na-stvorhran.html

A ešte prosím aké náradie potrebujem na montáž tohto zloženia?

Ďakujem

Kellys Coach Helix 2013 bike. I want to change the bottom bracket, it's been broken for 12 years and I only know that a 122.5mm axle length is needed. But I don't know at all whether I need a 68 or 72mm version. Does anyone have experience with this bike? I can't find a detailed description anywhere on the internet. Yes, I understand that it's best to take it apart and look, but asking hasn't killed anyone. Thanks in advance to a good person who will be willing to advise how to find out the diameter.

Hello, what is the difference between this axle and this https://www.mtbiker.sk/shop/komponenty/stredove-zlozenia/oska-stvorhran/shimano-tourney-bb-un300-68-mm-zapuzdrena-os-stvorhran.html.

Prosim Vas, mam stred BC 1,37 x 24T, 68x120.
Tento stred je 68x123, co cca 1,5 mm sirsi na kazdej strane. Moze to byt problem?
Alternativa je 68x118.
Co by ste mi odporucili? 118 ci 123
Vzadu mam 7 kolecko(Shimano 7-kolo, 14-34T) a predu 3 (Shimano Tourney FC-TY501 170cm, 48/38/28T).

Hello,
According to the specifications of the CTM Twister 3.0 2020 bike, a NECO 122.5mm axle should be installed there. Is it possible to replace it with this one? Or if not with this one, what could it be replaced with?
Thank you

Hello, I would like to ask (see attachment). Could you recommend me an accounting replacement for the work? Thank you.

Super. Ďakujem veľmi pekne.