Rank 2 is obtained from Bowlman in Blue and Mistman in White. Both are located in the battle terminal in the DNN studio. Just jack in, talk to them, battle them, defeat them, get rank 2.
Rank 9 is in HospComp 2, using the warp point in Beach 1 past the Hosp Security Cube, which is bypassed with the HospCode Mamoru gives you. There's also a blue mysterydata there.
By beating the guy who has Rank 8. That's sort of obvious. If you're having trouble FINDING him, a different matter entirely, try searching "what does Rednu3 mean in Megaman battlenetwork 3" among answered questions. Having written the answer to this question several times, you should get multiple results.
You take it back to the ghostnavi in the principal's computer. He will forget the clue to Rank 6, BUT, (of course) Chaud e-mail's you that Rank 3 posted on the ACDC BBS talking to you. You check out the message, and go meet him in Undernet 4.
Hospital Comp 2. But not from the hospital basement: from Beach 1 using the hospital code which Mamoru gives you.
Serenade from Megaman Battlenetwork 3 is a boy, as he is referred to by both Lan and Megaman as a boy, and holds the title of UnderKing. I cannot account for other characters named Serenade in the Megaman franchise, though they are likely the same gender.
That would be Megaman Battlenetwork 3, not 2. Evil falls in HadesIsle. Jack in to HadesNet.
Oh boy. Search Megaman Battlenetwork 3 White ROM on Google and you'll get enough hits on the first page to download at least 3. But don't ask that question. Please.
Fire + 30 is obtained from the bugfrag trader in Undernet 2 using the gargoyle on HadesIsle. Blackbomb 2 is behind Flashman's security cube.
The styles in MegaMan BattleNetwork 3 Blue are: Custom, Team, Guts, Shield, Bug, and the Blue version exclusive Shadow. They will be in tandem with the four elements fire, water, electric, and wood.
In Megaman Battlenetwork 3, the WWW ID is available from one of the Sci-Lab jobs, available from the Job BBS. I think it's the job called "Help with Rehab." Go to the Hospital TV to complete it.
Rank 10 is in HadesNet. Rank 9 is in HospComp 2 using the warp point in Beach 1. Rank 8 is in Undernet 3. Rank 7 is in PrincipalComp 2. Rank 3 is in Undernet 4. Rank 2 is in the DNN studio battle terminal. Rank 1 is technically in Secret Area 3, but don't worry about that.
Without a doubt. Whether it's to your personal liking I couldn't say, but just about everyone says that MMBN 3 is the best of the Megaman Battlenetwork series. Have fun.