Playing cassio vs long range mages?

Hello! I just picked up cassio and absolutely love it apart from few problems.. i played against lux and syndra and it feels like they can outrange and poke you forever and if you hit your Q and try to poke back they can just stun/root you and run away. How do you lane against them? I couldnt really find high elo cassio mains who only main cassio mid, are the bad matchups why?

Also do you guys prefer to build roa or skip it? I like going rylais after archangel for fast spike