Other people have basically said the same, but:
- You don't need that many overkill vias, especially away from the RF area.
- I would put footprints for a general pi network in the RF path, even if you just load it with 0
series and no shunts
- Use 0402 for the pi network footprints
- Maybe smooth curves instead of 45 degree bends, but it will make bugger-all difference.
- No thermal relief in the RF area
- Make the SMA centre pad the same width as the microstrip line
- Personally I would fill in the whole area around the SMA ground pins with vias which adds mechanical strength as well as electrical stitching.
(Hard to solder and impossible to desolder, though.)