You will get many answers here.
Your problem(s) will not be solved through forums and blogs.
You need to hire a professional color management consultant.
There are 2 ways of doing this, IMO:
1. Pay for it yourself
2. leverage all of your consummable usage (plates, paper, inkjet paper, misc. supplies) and ask that your current - ahem, or future - graphic arts supplier put a plan together to solve your problems. In return, they get, or maintain, your business.
If that is not viable, then call Bruce Bayne at Alder Technologies in Portland.
He is one of the best in the country.
Color Management, Support and Training Solutions
It sounds to me that your issues are very deep and include both employee knowledge/training and core color management of your multiple devices. Add to that a (presumed) lack of quality control processes and I would imagine it causes you to lose sleep at night.
With MIS, Web2Print, G7 and VDP all on the proverbial radar screen, you need to get your manufacturing operation under control so that you then plan for growth and further profitability.
You have some good iron and a mish-mash in prepress. Some OLD stuff, some really old stuff and some new stuff. Before you buy more stuff, budget $10 - $15K for someone to help you use the stuff you have. Put a plan together. get ready to modernize your facility. Get your sales people excited. Tell your accounts something new about your compnay.
Or sell your business now before your competitors steal your customers....;-)