Delta can't be changed by you. It has to do with the correlation between the change in the warrant value and the underlying share - in reality - it is the result of a lot of other fun machinations including time to expiry, volatility, the underlying strike price and another derived measure, the rate of decay. European puts are only exercisable on expiry date - but don't worry - in my experience there will be nothing left to exercise by then. In theory they are cheaper than American style and since you can trade the warrant in the market - it makes no difference anyway, I suppose. In my humble opinion warrants are a load of opaque nonsense so heavily tilted to the house that you need the stars to align before they work. They have some value as hedges in a market moving event, I guess. If you are confused - good - that means you are sane. Maybe look at CFD's/ futures and manage your margins very aggressively..(?)