@Aldin Tirak
As @Jay Hinrichs said, you probably will have to fix the sidewalk before you can record the plat.
The best way to know ANYTHING for sure is to go down to your development office and start talking to the folks that work there. Ask questions, hear the answers, ask more questions, don't get mad, just be curious and look for solutions.
You should try to get a good understanding of what/why it went wrong. I usually try to get the original contractor to fix before bringing someone else in BUT it depends on how bad they've screwed up - is this an incompetent contractor or is there a logical reason? In Austin, it's actually (sadly) common for city inspectors to fail inspections when they shouldn't.
RE: the architect
I would bring one in as soon as you're reasonably sure that you are solid with your subdivision. I don't work with online drawings so I can't tell you if it will work for you. Our Land Development Code makes that an unworkable solution.