Adwords new QS system looks into your overall campaign performance before it decides where your new campaign will be placed at. Look at adwords FAQ section: See what I mean (the bolded sentence)? Account history now seems important. Well, let's say my overall CTR in search campaign sucks, only around 0.9-1.2%. Do you think it's better if I create a new account and start everything from zero again? Remember that I only have one credit card and will use it for my new account as well. Is it really ok? PPC Coach said it's okay to do so as long as I link them up by using Google MCC. So even if I have 5 accounts and using the same credit card, as long as I link all of them up, that's really ok?
Sure, you can have multiple accounts. I always tell people not to bother with opening a new account unless you understand why performance was poor in your previous or existing account. If you're just opening a new account because you think it will make things "better" you'll likely find yourself in the exact same situation in the very near future.
I know what I'm doing, don't worry. AT least, I will be better than in my previous account. But is it really ok to use the same credit card number, etc.? No issues with Google?
I'm on my third account. There will be no issues with Google. However, note that you can't use your old account. If you do, you must notify Google, who will join the accounts. If you don't notify Google while continuing to use both accounts, they can ban you.