#2
It's not that hard of a tuning change, if you really want, just raise all the numbers on the 5th string by 2, on the 4th string by 2, and the 3rd string by 1, and it'll be the same thing. It'll be more awkward to play though compared to the original. If I were you, I would just get a tuner and quickly tune up, if your strings are a low enough gauge.

I'd also get a different taste in music than Hoobastank, but hey, to each his own.
#3
e--|---------------------------------|
B--|-------2---3---2-----------------|
G--|-------------------2---1---------|
D--|---------------------------------| x3
A--|-2h4-4---4---4---4---4-----2---2-|
E--|-0h2-2---2---2---2---2-----0---0-|

e--|-0---0-0-0-0---0---0-0-0---0-0---|
B--|-0---0-0-0-0---0---0-0-0---0-0---|
G--|-7---7-7-7-6---4---4-4-9---9-9---|
D--|-7---7-7-7-6---2---2-2-9---9-9---|
A--|-5---5-5-5-4---2---2-2-7---7-7---|
E--|-0---0-0-0-0---0---0-0-0---0-0---|


Verse

e--|---------x---x-x---x-x---x-x---x----------x---x-x---x-x---x-x---x-|
B--|---------5---5-5---5-5---5----------------5---5-5---5-5---5------|
G--|---------6---6-6---6-6---6-6---6---------6---6-6---6-6---6-6---6-|
D--|---------6---6-6---6-6---6-6---6----------6---6-6---6-6---6-6---6-|
A--|-2h4-----4---4-4---4-4---4-7---7-2h4-----4---4-4---4-4---4-7---7-|
E--|-0h2-----0---0-0---0-0---0-7---7-0h2-----0---0-0---0-0---0-7---7-|

That's it for the beginning, I'll finish it later. Even though some octaves are higher or lower, the chord structures are respected and the fingerings are rather easy. If you have any questions, feel free to ask till I finish it !