I'm a tightwad so bear with me.
I see it as a bike that is only 7 years old, unless it has more than 30,000 miles, although that's low considering i have a bike with over 150,000 miles but I digest...(yes, I know)...anywho, the bike you have is relatively young is what I'm saying. The components you have sound like they're still working fine. OK so you're claiming after 7 year the bike doesn't fit you quite right, why not take it into a shop and have a professional fit done since you haven't been able to dial it in after 7 years? The cost for that is about $175 plus parts, during the fitting process discuss with the fitter why it doesn't feel comfortable, once he has your information along with your physical proportions and bike geometry, then he can make suggestions on what is needed to improve the ride.
The other thing you can do if money is burning a hole in your pocket is to buy a wireless electronic component system, personally I think electronic systems of any kind is a waste of money, but that's just me. SRAM makes a very nice wireless system in their Red series that will cost about $1600 plus install. Wireless would be the only way to go on a bike that doesn't have the frame drilled out to accept running the wire through.
Or better yet, since you have $3,000 to spend, don't do anything on your bike other than the fitting and getting it overhauled, and instead pay off a credit card balance, or if you don't have a credit card balance, pay the money towards paying off a car sooner, of if you don't have a car loan, then put it towards your mortgage. Gee paying off bills ahead of time, what a strange and odd thought, you must think I'm really weird, but that's how I roll, I don't have credit card, I never get car loans, I don't even have a personal mortgage, the only loan I have is on one of my commercial buildings, and that loan is being paid for by the rents, even my other commercial properties are all paid for. I pay cash for everything, and credit cards are joke because the vast majority of people buy **** they don't need but can't afford so they put it on the card, eliminate the cards and that frees up not only money to put in savings but if you want to buy a house the amount of credit available (not the amount of any borrowed money, the total amount of credit available for your use on any particular card) goes against you and limits you by those amounts of how much you can borrow on a house loan, or in my case a commercial loan, thus reduces your buying power. And of course the same is true with a car loan.
Sure i don't drive around in brand new cars, but in my opinion that's a bad idea anyway since inflation hits new cars hard in the first 5 years, it's the worst "investment" a person can make. With today's internet capability it's easy to find 6 year old plus cars with low miles. I found a car for my daughter that was 15 years old, yikes you say, but it only had 32,000 miles on it and no rust (which is difficult to find here in NE Indiana), she paid $2,500 for it (used her tax refund), and it now has about 80,000 on it and it's never given her any problems. I bought a 94 Ford F150 supercab to use for hauling my trailer and supplies for my business in 2014 with only 64,000 miles and no rust, it now has 102,00 miles and still going strong with minor rust now just starting to happen, I paid $5,800 for it, but I'll drive it into the ground before I buy another. So low mileage low costing dependable vehicles that are older and don't cost much to buy are out there and relatively easy to find, and can be bought without going into major debt, or no debt which is the only way i fly when it comes to cars.
sorry, I jump off my soap box, i know it was a far fetched idea, back to what people consider to be reality now.