I am a bit troubled by this post.
Would you not rapidly need more weight for squatting and deadlifting than can be provided by two 50 or 70 lb dumbbells? Why do you recommend isolation exercises (bicep curls) along with all of the full body multi-joint exercises? Why do you recommend unweighted pushups in the weighted portion of the workout when the bench press is already there?
Progression every week in all areas is not a sustainable or a realistic goal unless someone is completely untrained.
Yes depending on how big you are 70lbs may be a little light for squat/deadlift- which is why I left the rep ranges open- tried to highlight should be getting close to failure. Try doing db squats with 70's 4x? and see how easy it is- again you may be an advanced lifter and this easy mode for you but based on the OP I just assumed he wasn't and advanced lifter. (It get's hard/dangerous to even solo lift up anything over 80lbs on your own to squat position). Deadlift could be higher- but again if you are not in a gym setting you can easily improvise to account for the light weight. I do 4x8 with 100's (highest weight in my gym) atm and that is a struggle during this workout- remember db is different then a barbell- typically can't lift as much.
I like doing standing bicep curl at the end of the workout bc they just help complete the big 4 lifts. It's really not what is important- I just like to add some arms in (normally it's standing bi curls with shoulder press super set but I didn't want to get into that)
Pushups are not really ideal- weighted pullups are what you want to be doing- I just gave him a suggestion of something to throw in there- another big muscle group- bc I doubt he is able to do pullups at work- if he can then that is what he should be doing.
Progression every week is very possible. Notice what I listed as progression- weight, reps, sets, rest time, lifting speed. You can easily keep everything the same and slow down your lifting speed= progression. Again based on the OP I just assumed he was a beginner/intermediate lifter. Of course an advanced lifter would not be able to accomplish this. The point is that it is VERY important to keep moving and not stagnate- every workout should be difficult and done at a very high intensity level (listen to your body here though)
And a full body workout is a very safe and reasonable workout for a beginner and is highly recommended by many bodybuilders/experts (can provide MANY sources). After you finish that program for 3 months and learn how to lift safely, what progression feels like, and what it really feels like to push your muscles you are well on your way to more advanced programming splits.
Again I like full body because of the recovery time and how you are less prone to injuring a muscle group. Leave the splits for the pro's.
Let me know if you are still troubled. I would say I am an intermediate lifter and accomplished this program this year as described and have seen very good results- diet is going to be your biggest factor though.
Also- Kettlebell workouts are good stuff too if that is the route you want to take.