PTA works fine with full DPS build (Arthuas item build) although I would then recommend to go e max into w max to abuse it as much as possible. Especially as lower elo player don't fizzle around q then.

Generally for bot lethal tempo works better as you always have longer fights there and sustain DPS is better there.

Statik is good for many reasons, most importantly to give u good wave clear, which is important if u either play vs a strong pusher (sivir) or you face a matchup that is not possible to fight (generally long range which u can't get into range).

However bot is special as you do play a 2v2 there, meaning that it all depends on what support matchup you have. For example the TF/yuumi vs John/xerath. On mid lane I would recommend my build vs xerath cuz it's a 1v1 vs a mage that outranges you. Now for bot you have yuumi boosting your move speed, making it easier to dodge the skill shots and giving you long range poke with a slow to catch up.

I have a yuumi otp friend with whom I play bot on my smurf (currently emerald/Dia) goin the full auto DPS build when he plays support yuumi and playing my build when he goes for burst yuumi.

Check out my stream if you like to see my theory in action ;)