What are you really looking for in upgrading? A lot of this is subjective so as you said there are many ways to get to Albuquerque but the other thing is not everyone is looking to go there or NM for that matter. Sound quality means different things to different people. I consider myself an audiophile but really I barely have a toe in that pool. I suggest you listen to a few different speakers you are considering before buying, they will sound different on a sound wall in a shop or in a different car than yours but you can hear differences between them.
- First has anyone heard of Phoenix Gold Speakers, they are not unknown but I can not find a recent review on how they sound and if people actually like them. They look very well made but not sure how they sound in a car, every speaker has a personality.
I haven't heard any newer offerings from them. PG used to be great, fell off into garbage almost in the Boss audio league, and has currently been coming back with some decent if not higher end gear.
- Is putting two ways in the door instead of component speakers and leaving or replacing the stock tweeters a good thing, I was thinking of replacing everything with two way speakers, in theory doesn't that sort of double the amount of speakers you have. (I went to another shop and they sort of talked me out of the component speakers with tweeters, I kind of got the feeling he just didn't want to mess with replacing the tweets).
Some people are happy with coax in the doors, which is all that really matters. Personally I would not as it will drag your image down with highs so low in the door and can get blocked by your legs, and bluredr it if keeping the tweets in the pillar. The factory system uses tweets in the pillars and mids in the door.
Also if only doing speakers keep an eye on the sensitivity rating. This is a measure of how loud a speaker gets with a certain amount of power, typically 1 watt/ 1 meter away. Higher numbers are louder and the scale is exponential, so 3db higher is twice is loud. Factory speakers while typically cheaply made usually have a high sensitivity rating. If upgrading to low sensitivity speakers they may sound better but you may lose a noticeable amount of volume.
- What does the cross overs do and are they important to how everything sounds.
Crossovers separate what frequencies different speakers play. You can easy fry a tweeter trying to get it to play too low, coaxial speakers typically have caps on them to protect the tweeters. Components will typically have external crossovers that usually keep highs out of the mids and lows out of the tweets and sometimes additional changes to improve the response overall. Some amps or DSPs(digital signal processors) have crossovers built in that let you tailor for the speakers/application.
- Lastly everyone wants to sale me padding, stuffing, rubber rings, etc what exactly do you need to properly install a speaker.
It's all in what your budget/goals are. for my front doors I have custom wood mounts for my mids, CLD(constrained layer dampener)i.e. dynomat type vibration dampener, closed cell foam, and MLV(mass loaded vinyl) to block sound from outside and the back wave of the speaker in the door. It makes a noticeable difference but adds weight and cost. I suggest you check out
https://www.sounddeadenershowdown.com/ if you want to read up on how all three work.