What will happen if I click "Erase all Content and Settings" or "Reset all Settings"?

What will happen if I click "Erase all Content and Settings" or "Reset all Settings"?

Looks like I'm going to have to go this route. Posted a message yesterday to try and just fix "Push". Couple hundred views but no response.

My goal is to re-jailbreak and unlock from scratch with out losing the 04.10.01 BB.

Phone stats -
iPhone 4 - AT&T/GSM
iOS 5.1.1 (9B206)
BB 04.10.01

I want to "re - jailbreak" and unlock my iPhone 4.
It's not able to receive "push" - iMessage, Find my iPhone, etc..
It also take crossed fingers and toes to hope it goes off the apple screen after turning it off and back on.
I.e., some times it will boot up on it's own in a few minutes, sometimes not at all. Sometimes works after I hold down power and home, sometimes not.
Sometimes if I leave it on the apple screen for 5 minutes or so and plug it in to my pc, it will boot a minute or so later, sometimes not.

Figure I'm ready for a clean install.

Right now it's jailbroke and I'm not sure what method previous owner used. Ultrasn0w is in Cydia sources but when I click on it the option is "Install" not "Modify".
Also have no idea what iOS and BB the phone was originally on. SHSH's are save on Cydia and TU.
Unlocked with Gevey sim.

Regards, Ken

 

After a bit of research. I ended up restoring with sn0wbreeze and a custom ipsw.