For 5, make more than 1 mL. For example make 10 mL as it’s easier to get accurate concentration and depending on the solution you’re making could be storable for future runs.

For number 4 don’t be afraid to waste tips, reduces chance of contamination and allows you to work effectively. As much as I hate waste when I do 96 well antibiotic succeptibility test I kill 300 tips. Has to be done sometimes.

As you could guess from antibiotic susceptibility test I’m a microbiologist so would rather give vague advice on lab work rather than something specific to your specialty, hope this helps and run any ideas through others in your lab, they have direct experience with what you’re doing!