Should I use a solid connection or thermals?
Rule of thumb: If it'll be soldered, use thermals. Period.

In my designs I always give my component pads thermals when connecting to a copper pour. Otherwise the heat will be wicked away as I am trying to apply solder (or as it is being reflowed) and you'll get uneven heating, leading to poor solder flow. I do not use thermals on vias, however, because they generally are not soldered. If I plan to use a via as a test point, only then would I give it a thermal connection to the pour because I may need to solder a jumper to it.