When it comes to testing I tend to favour the "if it works for an hour or two, then I'll run with it" method.
Generally I have found when O/C'ing things will fall over pretty quickly if the settings are too aggressive (voltage to low/CPU speed too high) and if you can test for an hour or two, with things running OK, then I've not experienced any failures when using the PC normally.
When it comes to voltages there is absolutely, no hard and fast, "This is the right voltage to use" no matter what you read on other forums or on-line. Each system is unique and will require it's own settings. Yes, what will work on one PC may well work on 100 others but this doesn't make it right for every system. That said, 1.35V is probably a good starting point for trying to get to 4.5Ghz. You may need to up the voltage a little or, you may be lucky and find that you can run nearer to 1.3V.
Honestly, don't get too hung up on what others are doing, keep things sensible, alter voltages and other settings one at a time then test. Don't make lots of changes at one go or you'll never know what is working and what is not.
Don't be afraid to go right back to Optimised Defaults and start over again. If you are keeping notes, you can soon get back to where you were.
And, most importantly, have fun, it's what O/C'ing is all about.
