So, after completing Ultima VII: The Black Gate and The Forge of Virtue, I'm going to play Serpent Isle. Before I do I have a couple of questions:

1) Regarding the expansion The Silver Seed: When is the best time to start it? Is it necessary to die to get the Amulet of Balance from the Monks at Monk Isle or can you get it normally the first time you arrive for plot reasons?

2) Are there any major glitches I should look out for?

3) What would be the best party to finish the game with? (Don't worry about spoilers. I already know about a very important plot event that happens later in the game).

1: You obtain the amulet the first time you speak to Karnax on Monk Isle, whether that's by dying and getting resurrected, or by visiting it as part of your normal explorations. It is probably best to wait until you have a new spellbook before using it though (something you will be able to do shortly after visiting the island normally).

2: The main one is the Xenka/Sacrifice bug, which occurs if you pick up the Serpent Staff improperly. There should be a few posts elsewhere in the forum describing the problem and how to deal with it.

It is possible to have a conversation with an NPC (the Chaos Hierophant) completely out of sequence by talking to several ordinary monster-ghosts in various places, most notably the burned alchemist's building northeast of Sleeping Bull. This does not cause any glitches in its own right, but it's a huge plot spoiler.

Very rarely you may get stuck with the 'cold temperature' condition sticking to you even when you have left the cold environment. Using a serpent gate to/from a cold location or traveling a normal path between cold/non-cold locations will generally fix this.

3: Aside from your original three companions (whom you can re-obtain), there aren't actually very many NPCs whom you can add to the party on a long-term basis. There are a few who will join you for a short time as part of a specific event, but the only two reasonable long-term prospects are Boydon (whom you can find on Mad Mage Isle) and Wilfred (who will only be available to join you after a certain disaster strikes). Of those, Boydon is the better option. He can't be resurrected if he gets killed, but Wilfred will permanently quit the group if his health gets low, so he's even harder to keep around.

You can also create and recruit generic automatons once you have the means to do so.