the pins fall out on new guns too, unless you get oversized pins or one of the custom trigger groups. not a huge deal if it's just a plinker.
the metal trigger housings are prefered by many, but the new polymer one is cheaper to make.
i bought the cheapest, which was from one of the guys on RFC. they came to $1.25 each, delivered. but i think he raised his price so now it's 4 for $6 or somthing like that. i haven't heard anyone make claim to be able to prove/measure/tell any difference between them.
some are harder, some are softer, some have a metal pin inside. they all seem to do the same thing. 15 years ago when it wasn't so easy to get them, my first 10/22 tire up the new scope i had on it after 15,000 to 20,000rds or so. that was back when a bulk pack box of Federal was $8.88 at WM and it only took me a year or two to kill that scope.
find what ammo your gun likes best. the Remington Golden Bullets don't seem to have many fans, so you can probably do better. without getting crazy i'd suggest trying a box of the Federal bulk pack and a box of their Automatch, both are available at Walmart.