I live in a two story (plus basement) town house.

Some of sinks and showers have very hot water that comes on rather quickly while others only gets warm and takes much longer to come on.

I would guess this depends on how long the plumping tube is to reach the sink/shower, but is it normal to have large swings?

In one shower I have to have it turned 'all the way up' to get enough hot water while in a sink elsewhere I would burn myself if I left the water running at 100% hot.

Unless you have really old fixtures... most showers have antiscauld mix valves built in which if misadjusted can limit the temprature a significant amount.

Sinks as a general rule... don't.

Was this always that way....and if not...what happened, meaning what has charged at the time it started?

All mixing valves can clog or partially clog. I would suspect that that one shower has a partially clogged hot inlet. One hand or two?

I think it has always been this way. I really noticed it over the past few months because of the cold weather. Also, I personally don't use all the sinks/showers in the house so it took me some time to realize.

It is both sinks and showers, for reference, the powder room water gets hot very fast, and is too hot when on 'all the way hot' the kitchen sink takes a long time to heat up and is only really gets warm/mildly hot.

The showers use a single spin dial for turning the water on, it spins about 3/4 or a rotation.

Single spin dial tells me this is likely a cartridge or ball valve depending on the brand. Once you determine the brand/model we should be able to help you clean it out.

I attached a picture of what the handle on the shower looks like, it is a Kohler 45796.

What about the sinks in the kitch vs powder room and the amount of time it takes to get warm/hot?

Your supply pipes do not make a loop but are more like a tree with a few big branches. Branches closest to the trunk (water heater) will get hot water very fast compared to a branch at the top. Also if you used hot water at the top branch and then check all other faucets they will be hot really quick too because hot water was drawn all the way up the main trunk.
I have to switch to me desk computer , iPad can't seem to open your picture

I understand that they are like branch, but what sort of range in temperature/time is normal? I am wondering if the 'branches' might not be setup in the most efficient manner

Efficiency is only as good as the maintenance that's done over time. When was the last time your aerators were cleaned and the valves flushed? Have you logged the time it takes the outer faucets to deliver hot water? Or logged the water temperatures to identify any variances?

Also note that the cold water in the line has to be displaced by the hot water coming in. Maybe the shower mixing valve needs flushing/cleaning/or replacing to bring better efficiency in the branch in question. The variables are endless. Start with cleaning the shower head and proceed to the next logical place and it helps to have a procedure to follow.

The house was fully renovated included plumbing under a year ago, how often is this work needed?

I haven't take any quantitative measurements, this is just something I noticed and wanted to get the opinion of others before I get the thermometer and stop watch out.

It sounds like the hot water itself is too hot for the house. The maximum temperature of hot water to the entire house should not exceed 125F. I would suggest that you purchase a cheap testing thermometer from a local home improvement store (see image) and check maximum temperature at one of the sink faucets that get real hot. Then, if you show excess temps., you can adjust the water heating source to the correct temperature.

Next, after the hot water temperature is properly set I would have you take maximum temp. reading at each shower valve. These shower valves have an adjustable TEMEPRATURE LIMITING DEVICE (usually under the trim plate or handle) that should be set at a maximum of 115F (plenty hot for showering). After you set the temperatures to the shower valves you can pop back and let us know what maximum temperature readings you are getting from the kitchen sink faucet and other problematic faucets as well. It is possible that the mixing cartridge to one or more of these has to be serviced in some way.

I would start there...

Mark

As Mark said get the thermometers and make sure of the things you notice.

Mark, thanks for the tip. I will pickup a thermometer and give that a try this weekend.