As far as I know there were no airfields on Bataan that could handle a B-17. In fact, I don't think there were any airfields on Bataan that could even accommodate fighters, but I may be wrong on that. The real problem with basing the bombers anywhere but Clark Field was that there were no support facilities (repair, supply, ordnance) anywhere in the PI but there. Even Del Monte Field did not have much beyond fuel and possibly some minor ordnance; it certainly couldn't have supported a sustained bombing campaign. As for MacArthur launching a counter-offensive, it's really a fantasy. He not only didn't have the capability to pull it off, but even if he had, it only would have been a temporary setback for the Japanese. And MacArthur's forces would have been in worse shape afterward, even if they had been successful. MacArthur's problems really started in August, 1941, when he deceived Marshall and Roosevelt into believing he would soon have 200,000 well-trained, equipped, Filipino troops. He never could have mobilized that many trained troops and he should have known it. If Marshall and Roosevelt have been aware of the real situation in the Philippines in the summer of 1941, they never would have wasted any reinforcements there.