I think you should definitely have the conversation with your landlord (LL) - seems like you're a great tenant & I'd bet he/she wants to keep you around. But don't give away all your marbles at the first meeting. Change your mindset from "will LL allow me to do this" to "I'm offering LL the best deal ever". Your offer to sign on long term, care for the property, make improvements should be viewed as very valuable. First offer a deal that gets you everything you want, but doesn't leave you with any financial burden.
Here's an example:
1. Offer to sign a very long term lease at a lower rate, but don't offer the upfront fee initially. Only use that as a last resort. When I rented a house I offered my landlord a significantly reduced price for 1 yr upfront rent & she took it. My rent was $900/mo and I offered $9k upfront for the year. Saved about $1,800.
2. Do not offer to pay for ongoing maintenance. You never know what could happen here. Some ongoing "improvements" like paint, etc would be ok. But not maintenance. As for the improvements to the property, I would think the landlord would be happy to have you add value to his/her property as long as you're not trying to do something crazy like a Margaritaville theme or something. Maybe just run some color swatches by LL to show him what you have in mind. Why would you want to take on the burden of ongoing maintenance without any financial upside?
3. Try to use your position of strength to get the landlord to meet you halfway. I.E, use your willingness to sign a long term lease at a set rate as a bargaining chip to get the landlord to chip in for some renovations. Lay out the projected costs of the renovations you desire, etc. Then, if you get pushback, come in and offer to meet half way on the cost.