Define a "small" budget. And your level of DIY ability. The only project that you mention that would be "small" as far as budget would be changing the paint. And that would only be DIYable if you own or will rent scaffolding and have a lot of spare time. If you have to pay a contractor to do it, you're not looking at a small budget project anymore.

Your home already has a strong SoCal Spanish influenced modern design. It will take quite a bit of money to take it in the direction that you want, with the projects you've outlined. It would be cheaper to keep it's current identity and run with it. Adding a tile roof would be all that's needed for that to happen. Or, with your preference for a more industrial type modern, do a metal roof instead. I could see doing it in a terracotta red or orange and that would both stay with it's current bones, and take it in the direction that you want to go also. Probably be cheaper than all of those other projects too, even though it's not a "budget" project either.

Budget: $10K
DIY level: 0
Getting what I want: Priceless

Can you post a larger photo? One that's taken directly in front of the home instead of on an angle would be nice. Angled photos are too difficult to photoshop (as are little photos).

You might be able to add the large window & replace the door for $10K

Painting alone will run 8-10K. That contraption for the entry way? Probably 15K. Replacing the window? (You can't "add" a window below it and have it work well at all, or be waterproof) Probably 5-6K. It's an expensive and large window you want to copy. Replacing the brick wall with a glass railing? 3-5K.

So, 50K approximately for everything you want to do. If you don't have a lot of money, you're going to have to get handy and learn to DIY some projects. It's the only way to stretch a budget. If you don't have time to develop DIY, then ditch doing anything at all. It takes time or money, or both to make the cosmetic changes that you want. And being that the changes are only cosmetic, and your funds are limited, save your money for the inevitable maintenance and repair that your home will need. Too many people forget that you need an annual budget for that first, before any improvements happen.

This does sound like a lot of work but it can all be done within reason. Depending on your DIY abilities, you can do the painting yourself and save thousands. The roof element and window will cost upwards of 20k. It may be above your budget you had in mind, but keep in mind the value you could potentially be adding when you are ready to resell. Curb appeal goes a long way. Consult with a roofing professional. In most cases they will give you all of the recommendations you need and even point you to some good resources, just don't let them talk you in to spending more than you need to.

Here is a link that might be useful: All American Exteriors