I don't even like Paypal credit since if you use ebay you almost must use Paypal. I just have Paypal charge my credit card and do not use Paypal credit system. If you give your Ebay Pw you probably have to give up your Paypal PW. Big potential trouble. I have heard about the snipe program and I am pretty sure it has been used against me in the past when I get outbid by 50 cents in the last five seconds.
I understand your concern with giving out your PayPal password or using the PayPal credit system. Fortunately, the app I bought (after following Paul's advice) only ask for my eBay password. Assuming I win an auction, the payment will be through eBay using my PayPal account, same procedure as normal.
I've manually sniped a ton of auctions in the last 3-5 seconds. It's not hard if you have the time to watch the countdown.
Those are steel pennies right cause of the copper color. If you had a roll of copper then you will be rich, but if they are steel cent and from the look of them they can go for around $100 or more.
And that's the way to do it. It doesn't matter if you're using an online service or an app, providing your eBay username/pwd to a third party is a risk. You must trust the publisher of the app or the company running the service, which I wouldn't.
Realistically, with your eBay user name and password I don't believe anyone can steal from you. Your Paypal user name and password is another story. Occasionally there is an auction that ends too late in the day for me to watch it until hammer time. And entering a "not to exceed" amount at eBay can be a real looser when someone keeps bidding for no other reason than they don't want to loose. But, to each his own. Maybe someday I will come back here and say, "you know, I should of listened to you." Living in a rural part of the US has taught me to trust someone until they give me a reason not to.
Certain sniping tools are fine. A lot of others use them and they do work. And at times you see hi-jacked accounts on ebay. Not sure how much it happens anymore, but probably more than I think. Not even sure how they get the information. For me - I prefer to figure out what I am willing to pay and bid that, then forget about it. Most of what I want does not come up in auctions anyway. Very seldom do I buy on ebay anymore. The only time I search raw coins is when I am trying to cherry pick a variety - but then most of the raw stuff I see I would not bid on. Just my 2 cents worth of opinion.