Yet another critique my itinerary post - London - 5 days

So, I need help with my 5 days itinerary in London. It's my first time solo and planning everything, so I'm quite anxious about forgetting important things or missing out on big stuff or messing up haha.

I want to avoid being rushed from one attraction to another. Did a group travel in Ireland last year that was that way and I didn't like it (though Ireland was amazing).

A couple of notes:

• I'll be arriving from Paris by Eurostar. This will be the second part of my trip, so no jetlag (I hope so lol).
• I have chronic back pain which is triggered when I walk a lot more than usual. This may explain some choices in my itinerary that may look weird for people. For example, this is why the day I'm going to the Hp studio in the evening, I don't have much planned and I booked some kind of visit London by bus to see things while resting. I considered an hop on hop off bus but I have to leave the city in the middle of afternoon for the hp studio so I feel it's not worth the 24h ticket.
• Replacing the changing of the guard at Buckingham palace with the horse guard makes sense? I'm 4'11 tall. I feel like I won't see a damn thing at Buckingham with the crowds lol.
• I love books. Any good spots to suggest (bookstores and stuff)? The exhibition at the British library seems to be close when I'll visit :(.
• I love eating and I pinned on google map a lot of restaurants already lol. Always opened to suggestions.
• I feel like going a bit away from the city in my last afternoon/part of evening. My plan before I even started to plan my trip was Oxford, but this will not be possible. I'm considering Windsor, Richmond (including the botanic garden) or Greenwich (market, painted hall and the museum). Is one of these choices more realistic or fun than others?

THE ITINERARY

Friday, day 1

• Arriving to London at 10:30am. Two options here: 1) going straight to my hotel close to Shoreditch and ask them to old my bag (about 30 minutes, maybe more with trafic); 2) Rent a luggage storage spot close to St Pancras.
• Lunch on the go
• British Parliement
• Big Ben (walking in front of)
• British Museum
• Words on the water bookstore?
• Check in hotel
• Dinner in Shoreditch + walking around

Saturday, day 2

• Westminster abbey
• Bus visit and afternoon tea (departure spot is close to the abbey)
• If time: find a park and do some people watching ;)
• At about 2:30-3pm: buy a sandwich for the evening and leave for the Harry Potter studio tour.
• 5pm: Harry Potter Warner Bros studio

Sunday, day 3

• At 9-9:30am: Tower of London
• Tower Bridge (walk on it, this is mosly an excuse for a cute walk beside the Thame river).
• Lunch at Borough market (maybe I can try to arrive a bit later than noon, like 1:30-2pm?)
• Optional: Southwark cathedral, but I don't think I'll have time.
• Millenium bridge (just walking across the river, though I'll probably see it during that bus visit).
• St Paul Cathedral
• Leadenhall market (photo op for the architecture and hp)
• Horizon 22 (If I'm able to book)
• Supper in a park (if weather permits) or maybe I can just find some place to sit to rest for a bit.

Monday, day 4

• Last opportunity to walk around Buckingham palace, St James park, etc.
• At 11am: Changing of gards (Horse Guards Parade) (arrive around 10:30-45)
• Lunch at Covent Garden
• National Portrait Gallery and/or National Gallery
• Trafalgar square
• Explore Covent Garden/Soho/Marylbone (maybe? It looks close). A few places I pinned on my google map: Goodwin's Ct, Harry Potter statue, Chinatown (though I may go there for lunch too...), Neal's Yard, Forbidden planet, House of minalima, Daunt Books Marylebone...)
• Walking around the city and St Dunstan in the East Church Garden (opportunity to sit there for a bit ;)
• Quick supper
• Skygarden or Garden at 120 at sunset for a drink (is one place and bar better than the other?)

Tuesday, day 5

• Walking around Nothing Hill/Portobelly road
• Hyde Park
• Kensington palace (I don't think I'm interested enough to get in)
• Lunch on the go.
• Afternoon/part of the evening away from the city: Windsor? Greenwich? Richmond? Or another?

Wednesday, day 6

• Leave for Paris at 9:31am. Last day in Paris then I catch my flight.

Thanks :)