I'll steal the info you gave pencil and piggyback on the thread, lol. Let's cover some basics about undaunted group dungeons (denoted on your map as an icon the looks like a square stone doorway with a plus sign on the lower right).

- most zones have an undaunted dungeon, then imperial city has two and shadows of the hist includes two.

- all of these dungeons have one skill point quest, and then about half include a second version of the dungeon with an additional skill point quest. You won't see the second version until you complete the first, or receive a pledge to do the second.

- all versions can be set to normal or hard mode in the group leader's social...group menu. The dungeon difficulty must be set before entering or it becomes a pain to change.

- generally these are made for four players, but many can be completed with fewer. I solo most normal dungeons with my vet toons no problem.

- you may enter and play these dungeons at any level. However, once you hit player level 43 (or 45...I forget) you'll get an invite to join the undaunted. At the undaunted enclave there are three quest givers who will hand you one RNG dungeon quest each day. This rewards a big xp gain and a chest key. So the most efficient way to play these dungeons is to wait and stack the dungeon quests and undaunted dailies...but if you end up collecting monster sets you'll be running these a lot, so stacking quests isn't imperative.

- save your chest keys (they stack) until you are cp160...even if that takes a long time. The only thing of value in there is a RNG monster shoulder piece. You want these to be max level gear, and fortunately the level procs when you open the chest so you can save up for a bunch of keys for down the road. Low level shoulders are pretty useless, but knock yourself out if you want to wear one at lower levels (they're one of the onlymset types that provides a buff for one piece, so if your setup has one odd slot open they're very useful).

- vet dungeons each reward a guaranteed monster helm specific to that dungeon on vet mode. Armor weight and trait are RNG.

- normal dungeons are mostly ok for any level toon. For vet runs I usually advise starting at 200+ champion points, depending on your skill level and build.

- group finder is one way to run these, but you might find people in the finder are looking to do very quick farms. They can be rude and annoying about this. It's rare, but I've seen complaints in these forums about a group kicking a lower level newbie rudely. But some pigs are great...just be aware they vary. If you want to run these and enjoy the quests at your own speed, belonging to some larger guilds and putting out a text chat can be a better way to get a group. And if you find some friends to do regular groups, it can make these way more fun.

Once you hit level 43 (or 45, I forget) and join the undaunted you can pick up dailies from each of the three quest givers each day. Each quest giver deals out a different set of dungeons.

The dailies are not automatically set to normal/vet...you set this via your social...group menu (even if solo, this is how you set any dungeon difficulty). Do this BEFORE entering the daily dungeon, and when it loads the mobs will be normal or vet based on the setting. Note: if you load the wrong difficulty, you have to exit the dungeon, change the difficulty setting, then relog the character. Sometimes this will reset the dungeon when you re-enter, sometimes you have to drop the daily and pick it up again. This is a arduous process...try to make sure the setting is correct before going in.

In answer to your question: yes. You can try to solo a 4 player undaunted daily. You don't have to be c630, you can try this at any time. A solo normal undaunted will be quite a bit more difficult than a solo public dungeon. And FYI, some bosses have a mechanic that stuns/traps you...the intent being to promote group work, where another player has to free you. As an example, in Fungal Grotto 2 there's a required boss that pins you to the ground and calls four spirits to tick down a guaranteed kill. The mechanic forces a group member to kill the spirits before the bomb goes off to free you...this dungeon can't be soloed because there's no way to escape this. This is rare in normal undaunted dungeons, but in some cases where this occurs the dungeon is hard/impossible to do alone.

When you complete the quest parameters for either the dungeon quest or the undaunted daily, you get the same reward regardless if you soloed or grouped. Imsolo these often, but I like running the normals with one other friend. It's like 5x faster.