Great guide in general. I main heimer, and I can't understand people who don't use him offensively.
I'd add in two pieces of advice. One, while laning, set up your turrets to minimize your opponent's ability to harass them. (Semi circle when against small AoE, very tight clump against Ashe, multiple clumps spread FAR apart against large AoE (nasus). Two, in team fights, set up turrets all along a lane BEFORE the fight begins. This is great for discouraging their champs to chase your champs if you lost, and for boosting your team's confidence.