Welcome and congratulations on your new SX/4! Sounds like you have some work ahead of you, but none of the problems seem insurmountable.
In terms of manuals, your best bet will probably be AMC Technical Service Manual (TSM). If you look at the blue menu bar above, you'll see an option for the EPedia, which is short for EaglePedia. In it you'll find copies of the 1982 and 83 TSMs. You can also find them on eBay, both hard copies and on disc.
And don't be afraid to ask questions, we're a pretty helpful bunch. And we'd love to see pictures of your Eagle!