Do you guys think it'll be safe to push 4.5+ghz?
I wouldn't do it. The VRM components on that motherboard are pretty cheap and the heatsinks are quiet small. I wouldn't go over 4.3Ghz. But it depends on how well your CPU overclocks.
Also overclocking settings in the BIOS will be limited because it is a pretty cheap motherboard.
Also overclocking will void the warranty on the Intel CPU. You should purchase Intel's overclocking protection plan to be on the safe side!
-Fishymamba Intel Response Team http://bit.ly/IntelRally
If you're gonna do it, check if no vrm or mosfets at the powerphases get overheated too much (keep max at 60°. see if you have a sensor somewhere at the Vcore (phase mosfets) )
Or in any case, see if your mobo gets a nice airflow, especially over those heatsinks at the cpu.
And finally, with 4+1 phase, keep a very close eye on the voltages. See that de Vdroop compensation doesnt deliver voltage spikes. I dont have experience with OC'ing (recent) intels, but I think its safe to say a stable voltage withing acceptable bounds would be welcome.