Hi,
Have you used the configurator tool online? http://www.ti.com/tool/OPT3101CONFIG-SW
This will simplify the process of choosing these parameters.
1) Given the requirements setting the high current to any value >100mA will work
2) see 1)
3) This depends…
Getting started
Training videos: https://training.ti.com/zero-hero-time-flight-training-series
Device datasheet: http://www.ti.com/lit/ds/symlink/opt3101.pdf
Evaluation
OPT3101EVM is available here: http://www.ti.com/tool/OPT3101EVM Device is pre-calibrated…