I can't really speak for the elite skill's power. I assume though that it is on par with the other summon skills. It doesn't give an advantage to people with it, just another choice of elite skill. It's not necessarily a better one.
The miniature Rytlock is a cosmetic item: it will make a miniature character run after you. The miniature doesn't fight, and can't help you in any way.
The Golem Banker is a convenience item, allowing you a fast access to your bank, from almost any place in the game world. It's a consumable, usable only once. Once used, it lasts 5 days.
The Chalice of Glory is a one-time-use item giving 5000 of glory to your account. This allows you to buy cosmetic upgrades for your PvP weapons.
The Tome of Influence is also a one-time-use item which gives 1000 of Influence to the Guild you currently represent. Influence allows the guild to do research, and unlock guild services. Note that an equivalent to the tome of influence is earned through the game, the Letter of Commendation.
All in all, it doesn't really give a gameplay advantage over people with the normal edition. You just get items which are mostly convenient, or cosmetic.