remember when changing your basal that any changes need to take place about 60 min beforehand (b/c basal you're "getting now" really is metabolically going to be "seen" after about 1 hour from the time of change on the pump). So if you're going to play at 4 pm, change your basal at 3 pm. Since you're just walking and throwing the disc some, I'd maybe recommend only a -15 to -25% change in your basal (assuming your starting BG is within your target range and you don't have any active IOB). And make the change for the duration of the activity. So set it for a reduced basal for about 1.5 or 2 hours. So the basal will "go back to normal" about 1 hour into your activity, and you'll have 1 hour left. This way when you get done playing, you'll have your normal basal "active" in your system again. This should help alleviate some of the highs that you saw from earlier basal adjustments. You could start there, and make adjustments up or done if you need more of less basal. As far as riding your bike, I don't know your pace/intensity or your duration, but I typically drop my basal a minimum of 40% (-40%, or 60% normal), and depending on my duration or intensity, I may go as much as -75 or -85%. I also take in 30-50 g carbs per hour on the bike.
With regard to your carb intake (in addition to your basal reduction), you might also try to take in 15g or so (roughly 15 beans) per hour, and then you could make adjustments (eating more or less beans) depending on your numbers. The key is that you're testing frequently when you first start experimenting so you can see trends and identify patterns. So testing when you make your basal adjustment, testing at the beginning of the activity, testing 30 minutes in, testing 1/2 way, testing afterwards, testing 30 min after to see if you're trending, etc. You'll use more strips in the beginning, but once you get the basic plan figured out, it will be really beneficial for you in the long run. Hope that helps some!