Does the atmosphere in a Rift influence how exciting or not exciting it feels? If yes, what Rift environments feel exciting to you? And which ones don’t?
I feel that the atmosphere does influence how exciting Rifts can be but it's a very minor and aesthetic level of influence. You can make the environment look as cool as can be but that won't affect how exciting it is to actually kill monsters, collect loot and interact with a party. I could tell you which environments I personally enjoy, but again I feel it is mostly irrelevant to the broader issue here.
The issue being that there is a serious core gameplay philosophy misconception between Blizzard and its community. Blizzard thinks that the most valuable aspect of D3 is the pve, killing monsters and finding loot. While I can respect that to a degree, i love killing monsters/looting myself, I feel the most valuable D3 experience is interacting with the community.
Do certain monster groups feel more or less engaging?
Every elite pack is engaging, in fact, i'd prefer more elite packs because frankly...trash mobs are garbage and rarely ever drop anything. I get more loot from barrels and loose stones than I do from them. As far as non elite monster groups, they are fine how they are...but again they rarely drop anything so who cares?
Are there any mechanics from other parts of the game that you feel would make Rifts feel more exciting? If yes, what are those mechanics?
Why not add events within rifts? Or side dungeons? Currently it's burn your way through to the next rift level, there's hardly any incentive for exploring the entire map. Some groups do, others don't and there's really no significant differences from choosing either...when there definitely should be more incentive to exploring every part of every rift level.
What's the most noticeable difference between a “boring” Rift and an “exciting” Rift for you?
For me, it's the players in the party. When everyone's communicating, linking loot, trading the legs they don't need for other random legs and whatever else...it's fun. When the party is anti-social and we just grind mindlessly...it's boring.
Do something about interacting with players before worrying about other rift mechanics.
As it stands, Blizzard is too focused on making the game itself better and not focused enough on giving us more ways to interact with other players. Develop Clans and Communities more, give us better customization of the social tab/friends list, reconsider your opinions about pvp ffs and generally give more quality to player interactions.
~ Give some incentives for joining a clan or community, bonus exp/mf/gold/whatever for partying with members (more-so for running full clan or community parties). Consider the wow treatment for clans and communities, give it leveling, perks, etc.
~ Give the Community CHAT channel its own / command. Make it more apparent that members can join the channel (maybe by default players are entered into the channel, they can manually exit it if they want and rejoin later).
~ Improve Clan and Community functionality! Make the message of the day show the entire post and not cut it off. be a little more lenient with the maximum number of characters allowed in clan/community info, details, posts, message of the day, etc.
~ Was also thinking it would be great if clans and communities could have their own icons, logos or something to allow for unique customization.
Social Tab/Friends List
Give players the ability to add custom categories. Sometimes I add people in game but don't want the grouped with my other good friends. Allow me to appear offline.
It sickens me that PvP is not a priority for this game. No matter how much you try and rationalize that PvP isn't good for D3, you are dead wrong. You're limiting players to PvE only when more than half of your community either are hardcore PvPers or generally like both PvP and PvE. As of now, you're catering all your efforts to about 1/3rd of the community who would rather ONLY have PvE...sorry for my language but that's complete bull!@#$.
General QOL for Player Interactions
~ List when party members loot a legendary item, similar to how it is displayed in clan chat once it's ID'd. This way players aren't rifting/grinding for hours not really knowing what their party members are even looting. Some people simply don't communicate what they are looting, and this seriously diminishes the amount of trading that goes on in parties. Which also players a role in how there's no need to communicate with party members to play this game...that should not happen. Having it auto listed would give people more of a reason to communicate, trade and admire what's being dropped in their games.
~ Remove BOA from Blacksmithing at least. What good is crafting if we can't share? You're only limiting the player base from playing together for %^-*s sake..