First note that the Enchanting page on the wiki says that Protection, Fire Protection, Blast Protection, and Projectile Protection are all mutually exclusive, but it looks like you can have Feather Falling on boots with one of the other enchantments.

The Armor page linked in the question has a table of "Enchantment Protection Factors" provided by each enchantment. I have duplicated the relevant parts of the table below:

Since increasing the level of the enchantment only increases the EPF, when trying to find the "best" protection it is only worth looking at the highest level enchantment. The article also says that in order to maximize protection from a particular kind of damage, you would need 25 points of protection for that damage type.

Since there are 3 different types of damage, one would need 75 effective points of protection, but since each armor can add either up to 11 points to one type of protection or 5 points to each type (which is like adding 15 total), the max is 60 effective points of protection. So, you can't max out everything. And plain Protection can't be maxed out at all. Therefore, the best armor depends on what you are looking for:

If you want to maximize the minimum protection value:

Put Protection IV on each piece of armor. This will give you 20 points in every type of protection. As a side bonus, if you put any level of Feather Falling on the boots, you will max out fall damage protection.

• Protection EPF: 20
• Fire EPF: 20
• Blast EPF: 20
• Projectile EPF: 20
• Feather Falling EPF: 38 (capped to 25)

If you want to maximize the average of protection values:

Again, put Protection IV on each piece of armor. Adding Protection IV to a piece of armor adds 5 to each protection type, so it adds 5 to the average. Adding any other protection enchantment adds at most 11/3<5 EPF on average.

• Protection EPF: 20
• Fire EPF: 20
• Blast EPF: 20
• Projectile EPF: 20
• Feather Falling EPF: 38 (capped to 25)

If you want to prioritize a particular protection type:

Plain old Protection:

Put Protection IV on all 4 pieces of armor.

• Protection EPF: 20
• Fire EPF: 20
• Blast EPF: 20
• Projectile EPF: 20
• Feather Falling EPF: 38 (capped to 25)

Projectile Protection then Blast Protection:

Put Projectile Protection IV on two pieces of armor, Blast Protection IV on one piece of armor, and Protection IV on the last piece of armor.

• Protection EPF: 5
• Fire EPF: 5
• Blast EPF: 16
• Projectile EPF: 27 (capped to 25)
• Feather Falling: 23

Projectile Protection, then Fire Protection:

Put Projectile Protection IV on two pieces of armor, Fire Protection IV on one piece of armor, and Protection IV on the last piece of armor.

• Protection EPF: 5
• Fire EPF: 14
• Blast EPF: 5
• Projectile EPF: 27 (capped to 25)
• Feather Falling: 23

Blast Protection then Projectile Protection:

Put Blast Protection IV on two pieces of armor, Projectile Protection IV on one piece of armor, and Protection IV on the last piece of armor.

• Protection EPF: 5
• Fire EPF: 5
• Blast EPF: 27 (capped to 25)
• Projectile EPF: 16
• Feather Falling: 23

Blast Protection then Fire Protection:

Put Blast Protection IV on two pieces of armor, Fire Protection IV on one piece of armor, and Protection IV on the last piece of armor.

• Protection EPF: 5
• Fire EPF: 14
• Blast EPF: 27 (capped to 25)
• Projectile EPF: 5
• Feather Falling: 23

Fire Protection, then the other two

Put Fire Protection IV on 2 pieces of armor and Protection IV on two pieces of armor.

• Protection EPF: 10
• Fire EPF: 28 (capped to 25)
• Blast EPF: 10
• Projectile EPF: 10
• Feather Falling: 28 (capped to 25)

Fire Protection then Projectile Protection:

Put Fire Protection IV on 3 pieces of armor and Projectile Protection IV on one piece of armor.

• Protection EPF: 10
• Fire EPF: 27 (capped to 25)
• Blast EPF: 0
• Projectile EPF: 11
• Feather Falling: 18

Fire Protection then Blast Protection:

Put Fire Protection IV on 3 pieces of armor and Blast Protection IV on one piece of armor.

• Protection EPF: 0
• Fire EPF: 27 (capped to 25)
• Blast EPF: 11
• Projectile EPF: 0
• Feather Falling: 18

If Endermen take any form of environmental damage (fire, water/rain), they teleport away and lose all interest in everyone who might have hit them before. so if you hit them with a fire sword, they will start burning and immediately teleport randomly for a few times until the fire goes out. If no environmental damage is dealt, they will pursuit you until they kill you or you run out of range.

Enderman as well have the habit to stand still then teleport if you stare into their eyes then lose contact. This can cause them to teleport around frequently during battle, so try to look down at their feet. In addition the teleport is in all directions, so they could be above you or below you in a cave after a teleport, unable to reach you until you get out of range.

The easiest way to kill an Enderman is to use their size against them. Build a 3x3 ceiling at 2 blocks height so that you barely fit under it. Then pull an Enderman to this location and he will keep running against the ceiling, unable to hit you and unable to look at you, while you can easily finish him off. You can as well use natural ceilings (leaves, rocks) at the same height instead of building one. Use a looting sword for increased chance to drop.

If you have any form of teleportation mod installed, you can do the same in the End world, which will thanks to the huge amount of Enderman gain you pearls very quickly. If the dragon is still alive, things get a lot more difficult. Then you need to find a location where the dragon is out of range. In some End worlds this is possible, in others the island is just too small for that.