Ross - no need to take the Arimidex - just go easy on the sodium, and drink more water and fresh juices, and perhaps a glass of wine or 2 at night.
On the form issue, I have no doubt that the form you used will produce muscle growth, but I personally almost always aim for full and complete form. Having said that, there are some top budybuilders who do "partial reps" - Jay being one example. But the lesson I think, is that unless you are one of the very best, you are going to get a hard time posting vids of partial reps (especially if you are claiming them to be legit reps - eg 10 reps bench at at x weight).
Next steps - post yourself doing those same movements as full reps and all your claims will then be legit.
All the best bro.