Many, if not all of the leaders, including city and guild leaders, will be chosen before the server is opened, and they will get to come in before anyone else to begin getting things in order. To apply for a leadership role, add which one you are applying for in the optional category of your application and why you think you would be good for that role. Also, it would help if your backstory worked with that leadership role, but know that getting the role is not guaranteed, so try not to change things too dramatically. Privilages will be outlined if you are chosen. Note that not every guild has a single leader.
You may create a character with any difficulty setting, but honestly, softcore is recommended. If you die, than you are considered 'Injured' for two in game days. When you are under Injured status, you must remain in the general vicinity of your home, you cannot fight, you cannot wear armor, and you cannot wear accessories. If you are a merchant, and you were somehow killed, then you can still go about your shop upkeeping, but with the above conditions enforced. The same goes for other shopkeepers or other laborers. If you are killed in PvP, the same applies, but if they were reprimanding you for theft, they will come to your home and retrieve the stolen items. Or, if they were either assassinating you or killing you in battle, then you are under an intensified version of the Injured status in which you cannot do anything for three in game days, so you may as well log off and wait an hour.
Note that at any time, you can choose to kill off your player, but others cannot technically perma. kill you. If you are hardcore, however, then you are under held under the assumption that your character dies permanently upon death, so be careful choosing this setting. If others are telling you that it would benefit the story if your character dies, and if they have killed you in battle, you are encouraged to consider the advice.