all guilds are different. some have strict rules, some are totally relaxed, many are somewhere in between. you need to find a guild that suits you and your style of playing for that city. no-one forces you to join any particular guild. if you can't find one you like, start your own. if you join a guild with rules and you don't want to abide by those rules, don't be surprised if they boot you. It's not fair to expect them to support you if you don't support others in the guild
The way Guild Expedition Championships are calculated means that if you go inactive for a while you are still included in the figures with a 0% participation, and the guild still has to pay goods for you when unlocking the GE levels. So if you know you are going away, let them know - and maybe offer to leave and rejoin on your return. Too many people just 'disappear' and nobody knows what is happening. If you are not in a 'fair-trade' guild, they won't have an issue with trades. If they are a 'fair-trade' guild - abide by the rules, lol