Facets mainly do 2 different things. 1)they passively give there thought and clarifications about situation and about basically everything. now that dose not mean they are giving good information or advices sometimes they do opposite of that. big part of things your character know about setting comes from facets
2)they may give you special dialogue or solutions to some problems.
for example someone may give you documents to evaluate rapport and panoply will look at it and say that everything looks in order apparatchik on other hand will find mistakes. and these can drastically change what happens after. same happens for other facets in other situations
aparatchik- you know most things about technical staff and can solve most technical problems. these facet will give you most technical information about setting and will generally can get best outcome's in burucratic disputes. also you can get in to screeching matches with half of characters because you think they are disrespecting you its very fun
rapport- you will understand most about characters why do they things they do and possibly even about story but are more useless in technical disputes.
panopoly- knows about how power works. panopoly probably gives best advices and while aparatchick uses authority for dick measuring contest panopoly uses it to do things
minor facets.
unto dust - you know that everything is going to shit. you will get some melancholy dialogue from him and will also be empesize when people have similar beliefs
razaor wire - survival instincts. if you like dont dying good facet.
frotres unbarred - nothing unusual with these one. you just sometimes talk to dead people and see visions from different time and places
in general i dont think there is one best combination to start with it just depends on what you like. and what kind of person you want your character to be.
