Please Gauge My Approach And Progress (Pointers Welcome)

I am a 58 year old 5' 9" male, and weighed 225 lbs. (yes I was obese) when I started this quest.

To make a long story short, I had internal injuries from an auto accident when I was in my mid 30's and could not exercise for a year. I got lazy and never started again. I made a career change at about 40 from a very physical job to computer programming. over 25 years of not exercising and sitting on my butt, I slowly went from 163 lbs. to 225 lbs. I was also a heavy smoker since I was about 13, and smoked about 3 packs a day.

I had to have surgery for diverticulitis a year or so ago, and during the pre surgery tests, I was told I had COPD, was told I could have had a mini heart attack at some point, and have developed blood clotting issues (one of which went into my lungs) and am currently on blood thinners.

I never really changed my diet over those years, and I have always eaten a variety of foods, many of which are nutritious, and some not. The only thing I really changed was my activity level.

Right after new years of this year I saw one of those activity trackers, and even though my first thought was that it was just a gimmick, I was still curious about them, so I picked one up. I set it to lose 1 lb. per week, and 5,000 steps per day, and started logging my food in the app. and I started losing weight.

I know it's all about calories in calories out, and I know many people on the forum don't think that exercise is important to weight loss, and may don't think it counts for anything, but I think it is at least (if not more important) than dieting alone, because it increases your fitness level, and makes your body work the way it should.

Anyway, here is my progress so far...

Walking
Been doing it every day for about 7 months
Started with 1 mile at a 3.5 mph pace.
Now up to 4 miles at almost a 4 mph pace

Biking
been doing it 2 to 3 times per week for about 5 months
Started with 3 miles at a 10 to 12 mph pace.
Now up to 10 miles at a 12 to 14 mph pace.

kayaking
Been doing it 2 to 3 times per week for about 3 weeks.
started out with about 1/2 mile at a 1 to 2 mph pace
Now up to 3 miles at a 2 to 3 mph pace.

Weight loss
I have lost over 35 lbs. in about 7 months

Smoking
Was a 3 pack a day smoker
Down to 10 cigarettes a day using electronic cigarette.

I chose these activities because walking and biking give a good lower body endurance workout as well as cardio, and kayaking works the entire upper body (both pulling, pushing, and core muscles) for endurance, as well as cardio.

I can pretty much eat the same as I always have because I am burning more calories by exercising, and my interpretation of calories out is not just resting calories. Many people discount this, but I feel that fitness level is extremely important in maintaining a healthy weight.

I was a fitness trainer in the army, so I have a basic knowledge of fitness, and I feel like I am making good progress so far, but things seem to have changed a lot since the 1980's, and I don't really have anything to gauge my approach and progress.

So please let me know if I'm on the right track (or not), and feel free to give me any pointers.

Thanks in advance,