UDOW has 3x leverage implied, but if trading on IB they will count this against your margin as if you had been 3x DOW yourself (and max portfolio leverage they permit overnight is 2x...).
Keep in mind these leveraged ETFs rebalance daily and so will suffer from decay where, even if the underlying instrument is flat after an up move cancelling a down move, the ETF will be down. If you intend to hold long term, it might be better to hold a non-leveraged ETF that you can rebalance manually using your portfolio margin.
Also, I wouldn't recommend tweaking algo for higher returns on the same data unless you have a sound explanation for why a given tweak should perform better. That is the path to curve fitting/over-optimization, which is arguably the most common problem in trading system development.
As for risk management, it is also a bit of a philosophical discussion as well as having technical aspects.
- There is an optimal leverage given market volatility and draw down characteristics that maximizes return. Assuming you have a representative sample series, you can find the optimal leverage factor for it.
- If you're using a strategy that simply aims to capture market beta (which is pretty close to your case), simply being fully invested when the alpha signal indicates it is likely sufficient, because it also means all your capital is put to work, and assuming you're not leveraged, the worst case scenario is limited anyhow. When you're doing a large number of trades in a volatile asset, all while being leveraged, the question also becomes "what is the maximum amount of money you're willing to lose in a single trade?", for which said risk management code is necessary. Beware though, stoplosses can fail during Black Swan events...