The US markets are definitely more suited to day trading compared to the ASX, since you'll get a whole range of big liquid stocks that will move $1-$5 each day. Comms are also based on units and not $$ value, so you can take on a much bigger position size and pay alot less in comms for it. So because of the lack of volatility in the blue chips, and the commission structure- the ASX becomes very limited in terms of retail day trading based on TA.
If you're swing trading over a couple of days then I think the ASX should be fine to trade. Remember US equities are alot more volatile on a day-to-day basis, so you will often get significant gaps up/ down on the open, which can be unpredictable and can potentially destroy your stops- leaving you with a big loss. So if you're swing trading US equities then you really have to put alot more effort into managing your positions. I think swing trading the ASX gives you more control over your risk, however there's going to be a limited number of stocks you can effectively trade. What time frames do you currently trade off?
Yes you're right, FP markets offers poor charting solutions for Equities. However their IRESS platform does offer good execution, even though the order inputs are old school .Purchasing live US equity data for $20 per month is very cheap. I use IQ feed as my data provider which costs around $90 per month, and use Market Analyst as my charting software. The software you chart on really depends on what sort of analysis you're doing and how serious you are about trading. If you're looking at web based solutions then I think prorealtime is one of the better ones, so perhaps check them out. Unless you're trading through a broker who offers data + a tradebale platform, then you'll probably be spending anywhere from $50-$200 per month on a platform & live data.
