[SweetSchollen]

I am unsure if what I did here is correct, I'll give my reasons for my actions and how the hand turned out, I want to hear if my reasoning is wrong, or if my hand was simply not good enough, or whatever.

First hand of a $10 5k guaranteed MTT on bodog. there were just over 500 people playing.
I have 88 UTG. I decide to even the field out some and raise to 100 at 5/10.
MP1 thinks for a while and moves all in for 1500.
MP2 calls.
MP3 calls.
I think for a while and call.

Now you may feel this is blatant spewing but bear with me for a second. My rationale at the time of calling the all in is that I want to get big or get out. I feel with a 6k stack at the end of the first hand, I can definitely devote my efforts to this tournament and probably get somewhere in it. I do feel that im good enough that on average I can at least get in the top 40% of players, but I feel like if I have the chance to quad up early I should take the chance. I have checked the odds of 8s vs various hands and I saw I was at worst like 15% to win the hand, just assuming noone is pushing with 8x or another 88 to completely wreck my chances. I'd say the avg % for me to win the hand is like 18,19,20%ish, assuming I never have the biggest pair in the hand. Is that a bad assumption? Also, I feel like at least MP2 and MP3 dont have me beat that often, depending on the player, I can see the call with any pair and any decent suited ace. Maybe I just underestimate their ranges, but I think that many people see the allin and just decide to try to double or triple up first hand(kinda like me).

The way it turned out was that MP1 had KK, MP2 had AJc, and MP3 had 33. AJ hit the wheel to win the hand.

I am not saying that this is a great play by me but I feel under my rationale, it isnt a horrible play either. I just would like some more opinions on this. Also, how do you feel about the situation if:
I have 87d?
I have a higher pair, at what pair does this become a good play?
I have two high cards, such as AK AQ KQs?
I feel I'm good enough to make top 30% on avg? 20%? 50%?
I raised preflop to 50? limped? Was the 100 raise bad? Did it have any particular good/bad aspects? What raise would have been best given my rationale towards the tournament?

Thanks for your input, this was an interesting scenario to me and I'd like to take away from it as much as possible.