MA cross is the 1st strategy I learned. I still use moving averages, but not the cross because one of the problems with it, is you have to always be in front of your computer as there is no way to pre program entries and exits related to the cross.
One thing I noticed that you may want to consider is simple is good, but no matter how simple you want to keep your strategy you need to include support and resistance lines in your trading method. I mention this because I didn’t see S&R lines in your indicator list.
This is only my opinion, but as far as missing trades goes, I wouldn’t worry about the trades you missed right now, I would concentrate on the ones you take. The reality is no matter if you’re trading 6 days or 6 decades, you will still miss good trades; everyone does. It’s easy to Monday morning quarter back when you look back through the charts and see a clear picture of what already happened. Every bodies system works after the fact. What you have to work on is getting a system that works for you in the present and future. Again only my opinion, but you want a trading method that fits your situation now. In the future your situation may change for example, allowing you to spend more time in front of your computer. But for now you have to use a method that works for you now when you can’t be in front of the computer and there are tons to choose from.
For example here’s one I use. 2 exponential moving averages with support and resistance lines. Works on any time frame 15 minutes and up as well as all currency pairs. If it were me, I would stick to one for now it’s much easier. Determine trend for the time frame you’re trading. Draw out your S&R lines. You can also use pivots, Fibonacci tools and or any combination of the three. The idea is know where support and resistance is.
Set one of the ema’s to 7 period, shift 0 close high; the other ema 7 period shift 0 low. You’re going long as soon as candle closes above top ema; short when one closes below.
Next since you can’t be there you need to use pending orders not market execution. So for example after your analysis, you believe the GBPUSD is in an up trend, so you put a pending order above the top ema 5 or 10 pips take profit 5 or 10 pips before a major resistance . stop loss at a major support. As you get better at support and resistance you can add pending orders. Here’s an illustration of what I’m talking about. But again there are tons of trading methods that you can use to fit your current situation.