I already placed a bid on ebay using automatic bidding, but now added a snipe-bid with my absolute maximum (same account name). Does this conflict? Any need to cancel the ebay-bid?

Thanks for your replies

It will not conflict.
However, if you placed the bid for the same amount as your snipe, there is no advantage on doing it.
If your snipe is higher, then it should cover you up in case if bidding will go higher than your manual bid.