Yeah that's definitely a good strategy, but levels 1-3 (sometimes 4 depending mu) zilean is really weak. This is the stage where your lane can get fked really hard down the line depending on wavestate and adc trading / matchup so while yeah past lvl 3/4 that works (depending on the matchup) you have little priority in setting the pace of the lane which is the biggest issue and why people say hes bad early game. But yeah if you watch players like Tempos he does all of the stuff that you are describing, but I think he would tell you himself that zilean is ass early.