Not the offset, in the past we had bearings without offset and the engines were still running fine and I do believe some 3rd party bearings do not have an offset. Ofcourse the offset does give a better support of the forces comming from the rod.
No, with bearings you have to take a look at the edge of the inner ring of the bearing, one side has a larger angled edge which has to face to the rear of the engine so the crankshaft will fit fully into the bearing. If you do turn the bearing otherwise the crankshaft will not fit fully into the bearing and when mounting the flywheel all will be locked up. And the large rounded edge on the crankshaft is pure for the strength, if it is sharp it will snap.....
And about crankshafts.... there are people here saying that the 14.5mm crankshaft is an evolution over the 14mm while simple physics does say there is a disadvantage and still I dan not convince people about it.

But hey, I do know what DJ feels, I did (sometimes still do) face the same problem too. If you are no Murnan, Clockwork, Sam, RCrenew etc then you are no serious person while all of them were in a same position when they have started.
I have learned a lot since involved with the devellopment of an engine and the experiments on many others and I do have some technical sight on things, without that you will never learn how easy some things are.....