Tried to find something on this but I gave up after an hour

So i was wondering if doing either imperial or stormcloack quests while youre a companion will have any affects. I read a book about the harbringers of the companions and there it waswritten that no companion shall inolve oneself in political issues.

So is that just something that's writtenin thebook and does not applyin the game?

And can one do quests for all guilds without any issues of one being offended or something?

Was wonderingif i could do the dark brotherhood, thieves guild, companions, mages guild and if any of the deidra quests have any impact on this

Thanks for any info