As to Contacts: There is no way to increase Loyalty on non-Mission specific Contacts, that means you are limited to 16 dice (Connection 5 x 2 + Loyalty 6) plus 1 die per 25% mark-up or wait for new Contacts to be introduced through individual Missions. In order to purchase anything up to Availability 12 off the shelf, you need a Connection 5, Loyalty 2 Contact (any other combination is too low) or a good face.
Most likely, everyone will take the blonde as a Contact though, heh. Just an observation...[/font][/color]
From the Missions adventures, in the
Picking up The Pieces section (this is the end section that details awards such as money, karma, contacts, reputation, etc, and is included in all Season 4 and Season 5 Missions):
Characters might interact with NPCs not specified by the Mission, and may earn these NPCs as a contact at Loyalty 1. They may also work with non-Mission specific contacts that they have already earned or that they bought at character creation, and gain a +1 Loyalty to these contacts. Gamemasters should not grant these lightly, and players should have to work to earn these contacts by going the extra mile to impress the NPC, offering up favors, or paying them well above the standard rates for information or services.
So yes, you can increase your Loyalty on your non-Missions characters, you just have to work at it and the GM has to agree that you're putting in effort into building the relationship. Now whether or not your GM bothers to use this is entirely between you and them.
Also keep in mind that you can buy extra dice for Black market goods, as per the SR5 book. It gets expensive, but you can buy up to 12 extra dice, which means that a maxed out Missions Contact will be able to get you anything in the core SR5 book, if you're willing to pay.
Lastly, not all contacts are able to do everything for you. the only contact who can get you "anything" is a Fixer. the actual Contact Sheets will have a "uses" line one them (It should have been on these, but I forgot to include them. I'll update them at some point in the near future). This outlines what sorts of things you can use the contact for. Some are only going to be good for information and rumors. Matt Wrath might hire out if you need some extra muscle. goober handles Armor, Weapons, vehicles, and Drones. Quantum Princess handles matrix gear. Sid is an all around Fixer (but he's a newbie Fixer, so he's not great yet

. Lothan covers Magic. Martin Tate acts as a street doc and can handle Cyebrware, but he, Maggie, Juan, and Sarah are all Corporate Mr. Johnsons as well. Which means they may be able to get you gear, but there maty be strings attached. And do you really trust corporate operators to get you gear you're going to be relying on?

Bull