To sum up the background if you just want to skip to the numbered questions: I have mid-low or economy class instruments, think a garage band with 2 electric-acoustics, bass, drums, keyboard, 2 mics.

Thanks in advance for reading my wall-o-text! I appreciate your help and suggestions.
Hello, I'm looking to inexpensively set up a garage band and also have the capability of recording somewhat decent sound. Just as a bit of background to give you an idea of what level of equipment I'm working with now and my price range:
Bass: Fender Squier P-Bass -unlikely to upgrade in the near future.
Electric-Acoustic: Just upgraded to a Fender T-Bucket 300CE from an $80 Walmart guitar I've been banging out tunes on for years. An additional guitar which will be used in the system should be exactly on par with the T-Bucket 300CE.
Drums: Pearl Export(+numerous additions- I have been mainly a drummer for the majority of my life.) I realize that in recording you either have to have a load of mics, use a drum machine, or just piece together stock audio.
Mic: Sennheiser E835 for lead vocals. I plan to purchase one additional mic of similar quality for 2nd vocals (not necessarily backup).
Amps: Bass-Gallien Krueger Backline 600 Head(300W) to a Behringer Ultrabass BA210(500W) cabinet.
I have two little practice amps.
Misc: Pop filter for recording and miscellaneous other non-electronic related things such as soundproofing are in place.

With that said, I was thinking of adding a mixer so that I can route multiple instruments and mics to a single PA speaker or to my computer for recording. As for live performance, for the most part this mixer would be just for practicing likely in my basement, but I'd still like the ability to connect monitors for instruments and output the full audio to an larger PA system.

My thoughts are the mixer would be used for the two mics, two acoustic guitars, potentially a keyboard in the future, the bass? (should the bass be routed through the mixer and then back to only the bass amp and not the PA? directly to the Bass amp and not through the mixer? I'm thinking that I won't likely have the funds to properly mic drums, but would consider mixers that do have the option (if price allows) for something like the Glyn Johns method.

As far as recording goes, I would like to make decent quality music (with the limiting factor being the instruments I'm using). A major deciding factor for me is the fact that I have several business-quality laptops none of which have firewire ports. I do not currently have an audio interface or any mic preamps. Given my current instrumentation, I was thinking the best option for a mixer would be between 8-16 channels, have built in preamps, and USB capability for recording to initially bypass the need for an audio interface. This is because I don't want my laptops to be the limiting factor in sound quality or processing. I understand that with many of these systems, an audio interface is still preferred because there can be crackling, etc. with the imperfect USB port.

To sum up my questions:
1.) Should I be using my bass amp and at what limit/size of venue do you think I should switch to using a PA? Should it be routed through the mixer even if I am using the amp? (Back when I played bass in clubs with my band, I always ignored everything that went on electronically, so I'm basically a newbie.)
2.) Is it -OK- to use a mixer that doubles as an audio interface for recording given the price range and quality of my instruments? (And the fact that my laptops are probably not the optimum DAWs.)
3.) How many channels for a mixer should I really be considering given the hypothetical setup of 2 guitars, bass, 2 vocal mics, keyboard, (answer this question with and without the option to do something like the Glyn Johns method or less mics).
4.) Given the answer to 3 and considering the quality and price range of the equipment I'm using, what are some recommended mixers? I was sort of considering something in the Mackie ProFX series, Allen and Heath Zed or ZedFX series, or the Alesis MultiMix8-16 USBFX or USB2.0. I realize there is a wide range or price on these, but I'm really taking a stab in the dark at what I should be looking at here. I've heard terrible reviews and amazing reviews of every product in existence. Again, use my instrument price and quality as a guide.
5.) What kind of monitors/Large PA speakers should I invest in after I get a mixer. Consider that this speaker will likely be played at low volumes of mixed audio in a basement, but I would consider options for using it at bars, etc. Could I potentially use the dinky amps I already have as monitors for the time being or at a venue? (This requires partial reference to the answer to 4, and price range ideas in 3.
6.) Starting out, I'd take any software that comes with a mixer, or use freeware. There is always the option to upgrade in the future, but I'll be trying to make due inexpensively to start. That said, are there any other essential purchases for taking the garage band to the next level (by fact or opinion- but specify which you are stating and your rationale).

Thank you so much in advance for reading my wall of text and sharing your knowledge.
I'll try to stay up to date with quick responses to any questions you might have. Keep in mind that if you're asking a question about my preferences, the answer is likely "I don't know". Like anyone I know I like options, but with options comes cost. In these questions I ask for you to simulate my preferences based on the value of my mid-lower range equipment.