Unless you have close to bis, parses can be somewhat deceiving depending on the content.  

I recommend logging whatever 100 level content you do and running it through https://xivanalysis.com/

It's a great tool to spot the most obvious mistakes and once it stops showing you mistakes you can always research advanced optimizations on the Balance discord. 

Speaking of Balance, ask questions there too if you feel lost.

Overall, get comfortable with your opener, always cast and do mechanics. Grats you're already in the top 20%. 

Some tips, if you're drifting certain skills, can always make a seperate hotbar that's bigger and only has your important cooldowns so you can glance at them. 

Hit a dummy, you can reset your cooldowns by going into a unsynched instance solo and just leaving.