Instead of tinning the pads just pad them with solder then use a solder sucker to remove it and it will sit flat. That way when you go to solder instead of just melting the existing solder you have on the pad use the solder on the roll to add so that the flux spreads properly and allows a good joint. The rosin core isn't bad, it's Acid core you don't want to use, but it's meant for soldering copper pipe and metals together. Acetone will work, but it may wash off the silk screening. SMD parts really aren't that hard to solder by hand. I am not in practice but built a prototype card a couple of weeks ago and here's the result:
