Pumppimp has given you a lot of information..
But another reason for the cannula's pulling out, do you use shower gel or a moisturiser as these can effect how well the patches stick, so ensure that the area you're going to use is rinsed really well and dry.
In these 6 years, I've only had 1 bent cannula, but I do self insert and use a angle set, as I;m very slim so don't really have any fat layer to stick it in.. So perhaps a change to to an angle set might resolve this particular issue.
As to pulling sets out, again I've only lost a couple, even though I don't use any safety taping etc, I've had my two dogs (german shepherds) entangled in the tubing, yanked by my grandson etc...
At first yes you are very conscious of wearing the pump, but you do get used to it, and it all becomes automatic, so just give it more time and it should settle down as you build up your confidence using the pump.