I have one question, guys: in the old days of 2e, Elven Chainmail was listed as being half the weight of regular chain and allowed your full Dexterity bonus to be used. Am I to assume that the same rule applies in 5e? If my character dons some Elven Chainmail, does my elven character get to use his full +3 Dexterity bonus in conjunction with this enchanted armor...? And speaking of enchanted armor, do other enchanted suits of armor, aside from the magical leather and studded leather, allow for usage of full Dexterity bonus? Thanks in advance for any insight on this issue.
Not to be a wiseass, but it's never safe to assume that rules have come over from other editions. Mr. Crawford specifically said in sage advice (I think on Dragon Talk) that a lot of people do this and it's not correct. 5E is its own set of rules and if it is not mentioned there, it's not there. Same goes, for example, for the 'surprise round' which many people still think exists in 5E (it does not).
And speaking of enchanted armor, do other enchanted suits of armor, aside from the magical leather and studded leather, allow for usage of full Dexterity bonus? Thanks in advance for any insight on this issue.
No one answered this part of Evan's question, and, since I have the same one, I'll repeat it. Are there any enchanted suits of armor besides the two mentioned above that allow for the full DEX bonus?
Nope - all suits of magical armor have the strength and dexterity requirements/restrictions of their base armor type.
They often have additional magical properties, such as the Elven Chain granting proficiency (making it good for a wizard for example), but I am not aware of any officially published magic armor that removes the dex limitations.
Bracers of Defense and similar magical items can boost your armor class without wearing armor and thus not impacting your dex bonus to AC.
2e was all about not getting hit, you really didn't want monsters in 2e hitting you since many had very negative effects when they did (level drain, save or die, so on) and characters most likely did not have the hit points to survive getting hit and if you did get hit, it took you weeks to regain hit points naturally (1 hit point per full day of rest).
5e knows you are going to get hit, it is built into the game, they give you ways to offset that damage (short rest hit die healing, long rest full healing, class abilities, so on). It is actually easier to get hit in plate armor/shield (AC 20) in 5e than it is in 2e(AC 0) due to the differences in how Hit Die Monster THACO and attack modifiers function. EXAMPLE, 2e goblin needs to roll a 20 to hit you in plate armor and shield, 5e goblin needs to roll 16.
But back to your original question, sorry No, armors in 5e and dexterity modifiers are limited by the armor type:
Light armor- full dexterity modifier
Medium armor- +2 modifier (more with feats)
Heavy armor- No modifier
IMO, They should have made elven chain light armor or allowed the dexterity modifier to be +3 or +4 just from a lore standpoint.