I'm doing some second-guessing here, but it seems that you must get stormwater from the back yard to the front. Since the former french drain is non-functional, I'm wondering if you can change it to a slot-covered trough drain that collects water at the critical places and then directs it via underground pipe to an outlet somewhere toward the front yard... ?? Since you won't be hiring a hydraulic engineer, I would lean toward keeping it oversized... thinking about those big storms and the fact that drains tend to collect "stuff" and become clogged. 4" pipe is too small. 6" or a pair of them would be better. (If you can figure a way to keep it above ground, even better.) The exact details of how you constructed it would depend much on how the plan shapes up and what else you're constructing. Being as it's your own yard and your doing it on the cheap, you might even consider constructing a removable slotted grate made of treated wood. It wouldn't last like other materials, but you could get a few years out of it. In regards to planting on the hill, I'd be in favor of getting rid of all grass, thinking it's not fun to maintain, creating instead a solid small flowering tree canopy that would be limbed up with a high ceiling. Below it, a single, solid groundcover. Trees that come to mind would be redbud or saucer magnolia, with a preference for the former. 5 trees in a double staggered row (3 at back, 2 at front would do it.) A super cheap groundcover would be virginia creeper as you can find it everywhere and start your own cuttings. It's pest free and grows about 12" tall. You'd be able to incorporate other plants at edges, once some shade is up and running, and in the sunny areas.

My guess would be Linaria. Here is a link that might be useful: Linaria

I would certainly not describe myself as someone who is sure of herself regarding design (I just got my living and dining rooms painted after about five years of paint samples taped to the walls) but this is what I did (I did not have a KD, for what that's worth): I spent a long time years  tearing pictures out of magazines (now I also save copies of pictures with elements I like from websites I browse). I saved the pictures (along with pictures I tagged in books) and when it came time to do the kitchen I went through them all and narrowed the stack down to ones I really liked. In some cases, it was a whole look or feeling and in other cases it was some specific thing, tile or a wood color or some other design feature. My husband and I also went on our local American Institute of Architects home tour every year (it also helped that for 10 years I was the editor of an architecture magazine but I'm a writer not, as I said, a designer. But that job did teach me to read plans and gave me an ability to visualize those two-dimensional drawings as three-dimensional spaces. So that was definitely a plus). In my case, I ended up with image after image of stained wood, Shaker-style doors, green tile (and more and more and more green tile), and dark counters. We knew we wanted matte black counters (although we were thinking honed black granite until I found GW; we ended up with soapstone). Oh and we love metal: galvanized, stainless, natural steel. So we wanted some of that. So those were our starting points. And that's pretty much what we ended up with: natural white oak Shaker cabinets, brushed nickel hardware, soapstone, butcher block, a black steel counter, and some other steel accents, stainless appliances. Oh and a green tile backsplash. I have a cart that slides into a spot under the counter, an idea I'd torn out of a magazine, and a bookcase built of steel uprights and butcher block, from another picture I'd saved and gave to our carpenter. I can't say I never lay awake worrying about how it was going to look. I did. Many nights. And every time a new element went into place I thought maybe I'd messed the whole thing up. But lots of time thinking about what we wanted before we started, lots of poring over magazines and books and websites, made me pretty sure of what I liked and of what elements it would take to create the kitchen I wanted. Sorry for going on so long. I have no idea if any of it's helpful. I came to GW after many of our decisions were made but I think there's much to be said for the Sweeby test: how do you want your kitchen to feel, how are the various elements contributing to that feel. The idea of writing a mission statement for your kitchen seems like a good one and I guess that's basically what I did with all my pictures. There must be many ways that people end up with the beautiful kitchens I see here on GW (certainly much more refined kitchens than mine) but our process worked for us and we ended up with a kitchen that, two years later, I still marvel over and love.

First you need to decide how to use the porch. Are you a sit on the front porch type of person? With food or drink? If yes think about adding another seat and some type of table. Is this an area to stand around before coming into the house? If yes your bench is enough, I would consider moving the bench to against the wall to give you more room around the door and color on against the wall. Regardless of how you use the porch put art on both walls. Put colorful pillows on your bench, I like it, colorful pillows will make it stand out more. You might want to consider painting the bench another color to make it stand out. You have a blank slate have fun with the area. Art on the wall can bring in color that plants would, but with fewer limitations, and upkeep.