First things first -- commingling service and non-service conductors in an auxiliary gutter is unwise, despite being Code-legal, so you were right to correct that situation.
Second, the grounding electrode conductor (and water system bonding termination) connecting into the meter pan grounding busbar is almost OK even though no separate EGC is routed from the meter pan to the service disconnects, as it falls under 250.64(D)(3):
(3) Common Location. A grounding electrode conductor
shall be connected in a wireway or other accessible enclosure on the supply side of the disconnecting means to·one
or more of the following, as applicable:
(1) Grounded service conductor(s)
(2) Equipment grounding conductor installed with the
feeder
(3) Supply-side bonding jumper
The connection shall be made with exothermic welding or
a connector listed as grounding and bonding equipment. The
grounding electrode conductor shall be sized in accordance
with 250.66 based on the service-entrance or feeder conductor(s) at the common location where the connection is made.
My prime concern here would be that that ground busbar may not be accessible due to the utility seals on the meter pan -- if that part of the meter pan is customer accessible though, then that's not an issue.
Third, the gutter bonding arrangement follows 250.80 and 250.92, so that's hunky-dory, except for the fact that the 6AWG copper wire used is one size too small -- 4AWG is the correct size system bonding jumper as per table 250.102(C)(1).
Finally, the bond conductor between the gutter bonding point and the service disconnecting means is...redundant. 250.92(B)(1) calls for service equipment enclosures to be bonded to the grounded conductor using a Code-compliant means, and the green screw in your service disconnect enclosure's neutral bar certainly qualifies!
So, you can remove the redundant (and undersized) bonding jumpers in the auxiliary gutter, as well as the existing gutter bonding jumper, and use a length of 4AWG bare copper to bond the gutter to an accessible point on the grounded conductor (such as the existing meter pan grounding busbar) as per option 1 in your drawings. If the existing meter pan grounding busbar is indeed inaccessible, then the grounding electrode (GEC) and water system bonding conductors will need to be replaced with longer ones that can be run into the auxiliary gutter, as that's where a grounding tap for this stuff will need to be installed, connecting the service neutral to the GEC, water system bond, and gutter.
Your Option 2, however, probably won't fly -- the use of a separate bonding conductor alongside the service conductors might get dinged by the AHJ as a 250.92(B) violation, and is a waste of copper anyhow! (In fact, a cleaner solution than Option 2 would be to remove the dang PVC nipples and replace them with rigid metallic ones fitted using listed bonding-type locknuts.)
As to your updated plan, that appears mostly correct -- 4AWG is big enough for the job as per table 250.66, while the bond of the grounded neutral conductor to the meter pan is in accordance with 250.80 and 250.92. However, I would route the grounding wires for the CATV and telephone systems directly to the gutter grounding and bonding busbar, using it as your intersystem bonding termination as well. This treats the auxiliary gutter as "an enclosure for service equipment" for the sake of 250.94 and eliminates the need to make irreversible compression-type or exothermically welded taps on the new grounding electrode conductor. Finally, I would remove the existing grounding electrode conductor and water system bonding conductor to avoid inadvertently paralleling the neutral and possibly causing stray currents in the water piping or grounding electrode systems.
No need to worry, a 200 amp supply box has more than enough reserve to power your garage. If there ever was an exess draw - anywhere in the system - your circuit breakers would react by tripping.
You could run a sub panel to the garage, in case you ever wanted to use more powerful tools in the garage.
Install a 50 amp duael breaker in the panel, run #6 three-wire line to the garage in a plastic conduit line and connect it to a sub panel circuit box in the garage. Then you can run individual 20 amp circuits from the sub panel to power outlets in the walls and another circiut to your workbench, etc. you could run 3 or 4 20 amp circuits in the garage. This would leave you in good stead for any future needs in the garage.
Best Answer
The calculated load valve is for new services, for existing services you can measure the load on the service. Do you want to put in a new service? Did you just win the lottery?
Putting in a new service in many states requires you to update everything to code and in the last 32 years there are a huge number of changes that will be required. Would I even consider a upgrade from 200 to 225? Not a chance, I would not really think about it until 250, and at 300 sure it makes sense.
I have measured many homes and have never found one at 80% in fact most residential homes even in all electric are 80 amps or less on average.
Now to help you feel better about your home, have you changed from all incandescent lights to CFL or LED? CFL cuts the lighting load in 1/2, while LED gives close to an 85% reduction. Has the furnace been upgraded to a newer heat pump? Have the refrigerator, dishwasher, and oven been updated to energy star devices?
All these upgrades relieve the actual demand and the code panels are looking to change the load calculations for this reason.
What would an electrician do to evaluate the demand? They would pull the dead face off your main service panel and clip a clamp meter on one leg then the other, then tell you to turn on the oven and heater or air conditioner and all the lights and repeat the test heavily loaded. As I just described it, I would bet that your home probably will not be drawing over 125 amps.
If you want to get really crazy add the washing machine and dryer, and turn the hot water on. Unless you have an electric on demand water heater, you will probably still be below 180 with just about everything on at the same time.
You can do this same test yourself with a amp clamp meter costing under 100$
If you see an imbalance from 1 leg to the other this may need to be balanced, but don’t balance with crazy loads; balancing should be done with normal loads that you have running.
Just FYI car chargers are calculated at 125%.
The feeder to the house only has to be 83% not 125 because of the diversity of the load, even turning so much equipment on I would be surprised to see 80% and there are additional safety factors built in.
For example a 14AWG wire is limited to 15 amps by Code, but in a equipment panel from memory it is over 75 amps. There is a huge safety factor.