Hi Andy,
I assume this is sarcasm but, just in case, TA is Technical Analysis, i.e. the study of price charts with (or without) indicators and other tools in order to make trading decisions.
I can't really help with this as I don't know what market(s)/instrument(s) you trade, your style of trading or your objectives. In other words, the techniques used for day trading may differ to those employed for position trading. Similarly, the objectives of the former may - for example - be to trade a reversal to the mean (which you've indicated on another thread), while the latter may be to ride the trend until 'the bend at the end'.
Of the four MAs, the 20 and 50 will best approximate what I was trying to show in the Dow chart, the other two indicate the long(er) term trend and are commonly used on daily charts. You can play around with the settings - they almost certainly won't be fixed - to see what works best for you.
Pretty much - yes. The 20 relates to the number of candles/ bars on the chart. So, if you're looking at a 1 minute chart then, as you rightly say, it's an average of the last 20 candles/ bars, i.e. the last 20 minutes. However, if you're looking at a non-time based chart (like my Range chart of the Dow), then it's still the last 20 candles/ bars on the chart that are being used to calculated the MA, but there's no indication of time.
If you want more feedback on this, I suggest the way forward wold be for you to post a chart of the FTSE and indicate where and why you entered. That will provide the necessary context for subscribers to your thread to suggest ways you might exit.
Tim.