Yes the lock rings only job is to hold the bearing in place from the backside and the outside bearing retainer plates job is to hold the outer bearing race in place and keep from spinning from the outside. for a yard car that won't be put on the road for quite awhile I would have put in run of the mill oil with a separate zinc additive but to each there own. As far as a return line it was used on all high performance and also a/c cars because of the increased under hood temperatures and associated vapor lock problems. If it were me I would get the one with the return line and just plug the third nipple for now and when it comes time to get your new sending unit get the corresponding one and add the line. The tools I am referring to are here https://shop.snapon.com/product/Brake-Spring-Tools/Brake-Spring-Tool/BT11 and here https://shop.snapon.com/product/Brake-Spring-Tools/Brake-Retainer-Spring-Tool/B1356E I have snap on but other company's make the same tools which will work just fine for a hobbyist. Remember to get a hold down tool with a flippable head for the smaller and regular sized springs. Also if you don't have one a brake spoon with angles like this one will help out with the adjusting https://shop.snapon.com/product/Automotive-Brake-Adjusting-Tools/Brake-Adjuster/B3404B Yes lube on both ends the washer goes on the small end and yes lube the insides only. When you say brake grease It is just a generic grease some company put that name on. I have no idea of it's thickness or it's ability to withstand low and very high temps so your guess is as good as mine. No other clips but can't see by your picture if the equalizer bar anti rattle spring is in place. Also look at the teeth on the star wheel closely if even one is nubbed off on the edges when the wheel turns to that spot the self adjuster mechanism will stop functioning so just replace.