Couple of comments Dentie,
Firstly, ASX usually doesn't usually commit trades, it would be your broker. The ASX doesn't even usually get involved in suspicious trading from the buyer/sell side, they normally question the company as movement of such magnitudes is normally from some information being available to few, that should be available to everyone.
Secondly, your broker has every right to forbid a trade if it feels that the trade is not in your best interest. For example, moving the price 20% up, is not really a good trading strategy because it shows the stock is illiquid and if there is an announcement or something which was coincidental, it could cast doubt on you willing to pay 20% higher than current market prices.
However, on that note, several brokers will let you trade whatever you like. I've never been refused trades via Commsec however I've been trading with them a very long time. Other people have told me they've had issues where I have not. I think the broker relationship you have can alter the ability of what you can and cannot trade, if you have doubts, ring your broker and ask if those restrictions can be removed (as you see yourself as an expert trader and take full responsibility).
Finally, you can request those share registries from the company directly also. If you think it's in their best interest they may look in to it, or in rare cases give them to you for free. The company gets an update registry daily in most cases.
Manipulation is something you shouldn't worry about. I know it sounds silly but in reality it's going to happen regardless and you need to work in such an environment. People will always try and squeeze the market for any money they can, that's human nature. Work with the tides and you will find it much easier to get your boat where it needs to be
