i need help with scouter (machinist) ark grid

i made a scouter (machinist) with the new express event and want to know what the options i have before opening the relic ark grid chest

1- what the best ark grid option rn ?
2- what is the most comfortable ark grid combination
3- what tips can you give me in raid ?
4- if possible any kind of extra information would be nice

"i did read the maxroll guide and understood how zero sync skills works also i played scouter before ark passives so i have some knowledge "