If you want to get 1k hours with no temps and waste 5 years of your life then go for it, i would recruit temps, it doesn't show weakness at all. In fact if you are a tower guild and don't recruit temps you are not using your resources. Lastly about the guild loyalty, there are two options. Make a it so you can only join one guild, and if you leave you cannot join another guild for a week. This would stop guild hopping alltogether. If that's a bit to extreme then just make the ability to join 2-3 guilds, but keep the 1 week affect, if you keep that no matter which route you take you will not have guild hoppers and if you do only a few.