Your complaints are very commonly seen here. I would recommend posting this in the New Members forum, so you can discuss details back and forth.
In general, the higher the wattage you are vaping, the less flavor. Best flavor for me is a 3.2 ohm carto, fresh, on a 3.2V battery, like an eGo or original 510 batt. Heat diminishes flavor, while increasing vapor. That is a general rule of thumb. Heat produced is proprtional, essentially, to wattage, which is power, P:
P = V*V/R where V is voltage of the battery under load, and R is the coil's resistance.
So a 5V PV with a 2.5 ohm atty will give 5*5/2.5 = 10 watts of power. The eGo is about 3.4V, so you can calculate how much power each of your attys/cartos give on this battery and get a good idea of the relative heat of each.
Another thing about flavor is that, like with eating, it does diminish in perception over time if that flavor is constantly being applied. So it could be that you are just not giving your mouth enough time between hits to refresh. Put the PV down for a bit and see if flavor returns.
CE2's are very different than regular-style cartos. They are almost like a LR carto even if they are labeled as 3.2 ohms. I find them to be too finicky in general, the juice needs to be just the right consistency to wick well, you can't hit a lot on them in a short time like a regular carto, or they do diminish in vapor and get burny. I think they are on the right track with the E2 technology, but they have a ways to go. New versions are out now (#5 I think. I have version 4's), so they might be getting better.
For regular cartos, the juice needs to be on the thin side. The juices I make for cartos are considerably thinner than those I use for dripping. I'm not going to discuss the original carts too much, as it is probably the least effective and highest maintenance of all, and I gave up on them, including extensive modding, long ago.
Another option is a juice-feeding PV, which holds a bottle of juice inside and you either squeeze the bottle or there is a pump button you press to send juice to an atty. Bunch of models like that, haven't tried it yet, but people love them, mainly for the long-term hassle-free vaping and good flavor and vapor.
Another option is a tank system, which is a special atty/cart combo where the cart is a container that holds juice and feeds it little by little to the atty bridge. Mixed reviews on the tanks, like the eGo-T. They work well for some, and for others they leak and/or do not deliver juice well.
Then there are the new dual-coil cartos. Haven't gone there yet, but they seem to be huge on vapor, but drain the battery about twice as fast.
Personally, I like Boge cartos on an eGo or KGO (similar) the best of anything right now. Most people love Boge's, me included, and some do not. There are also SLB's and other brands. For me the Boges are head and shoulders better. I use mine with a drip tip, and just occasionally top them off throughout the day. I can get a couple/three days out of one before it needs a bath. Like you I do not like to throw out vaping hardware unless it is dead. I soak mine, cap removed, in vodka for a couple days, then flush with hot water and dry in a 250 degree oven for 30 minutes or so. I get several cleaning cycles out of mine before they are too far gone, which can mean many weeks of use, rotating them with others.
I will answer your last questions with these words:
You might be doing something wrong, but without more details its hard to say. So post on New Members or in the eGo forum or cartomizer issues forum. This requires a conversation, rather than a simple answer.
Its not too much to ask in theory. Its what we all want. I get that now with my gear, which is pretty much like yours, but of course there are those that want lots more power, juice feeding, variable voltage, and other more advanced and generally expensive changes. With some back and forth discussion, I think you should be able to certainly be happier with your gear, which is quite good BTW, or else find out the info needed to get what would be better for you. Be patient! E-cigs are far from perfect yet, and it takes time to learn how to use any setup properly.
good luck!