I've also primarily roleplayed in text, specifically on MUDs, including one very hardcore RP MUD that had hard-coded realism (no character levels, permanent death, inventory based on what a character is holding in right and left hands, etc.).
I think LOTRO makes more effort to allow the text in the chat box to represent what is happening the graphically-rendered world than other MMORPGs that I've tried. You can perform a hard-coded emote with a graphical animation but use your own text for the input window. Also, you can insert the name of a player or NPC into your emote by targeting the character on the screen and typing ";target" into the emote.
Originally Posted by Haruven
So, I could type "/kneel drops to one knee before ;target, bringing his fist to his heart in salute." The visual animation would show my character kneeling in the direction that he was facing, and the chat box would output "Fyndril drops to one knee before Gandalf, bringing his fist to his heart in salute." (Assuming I was targetting Gandalf, for example.) That doesn't allow as much control of emoting as MUDs or MUSHs do (for instance, I don't think you can get rid of the space after your character's name in the text of an emote, in order to put an apostrophe -- "Fyndril's hand clenches into a fist"), but it's still not bad.
Fyndril of Landroval, Band of Hope (Man Hunter)
Caerlon of Imladris (Elf Guardian)