Here is some feedback and also some questions -
Are you focusing on the 50 or also on the 100 ?
I think 300 warm-up is not enough - most people need at least 15 minutes - whatever that means in terms of distance.
Sprinting like this 3x per week is actually quite a bit - I can only manage it 2x per week with the lifting. But great if you can handle it.
Even for sprinters - there still needs to be some sort of periodization. When is the main meet you are shooting for ? How many weeks out are you and then build some sort of plan from there. Another question is - what other tools can you use - and want your body to learn how to use >> paddles, fins, resistance training.
Here is a rough example of a season 12 weeks just focusing on the sprint workouts:
3 weeks of technique and getting used to resistance work - you can sprint maybe at 90-95% level and still focus on technique - or use the fins to help you. Learn how to use a parachute / big trunks / or a T-shirt and do 8-12x25 sets with rest. Start out easy - see if your arms and shoulders show any problems.
3 weeks or building strength - Use the sets you are already doing - add in 10 seconds of fast sculling before some of the sprints / or 25 all out kick + a 25 sprint. Build the resistance training further - getting closer to max efforts. You can also add some sprints with paddles. Mix that up with just regular sprints.
3 weeks - just power work - use the resistance training - maybe do 6-8 sprints with a parachute and then 2-3 without and then 2-3 with zoomers and then 2-3 with zoomers and paddles. Again always have a regular sprint day as well.
3 weeks of fine tuning and above race pace sprints + Taper -- use a band to assist you. Running starts are great or zoomers.