I'm not sure that's mix of soil is loamy enough for roses, you might want to think about adding some peat moss to the mix. I don't have tree roses, but I do have about 30 rugosas, floribundas and a few HTs. I've been growing roses over 25 years. I normally add lime and a banana peel to the hole for a new planting. I use compost tea for fertilizer. I would dilute that fish emulsion do to about 1 teaspoon per gallon. I think I'd skip the fish parts, myself. That is NOT is going to smell good. whew! It is always easier to make it slightly stronger if you need to, easier to add to than take out.
Good luck, I was eyeballing a couple of lovely tree roses this weekend. DH got all fussy......grin. Heck he wouldn't have to dig a hole for those! Men, whatca gonna do. LOL
Your peach tree is producing eatable fruit and needs that kind of soil mix to make it work and keep it healthy.