These seem like pretty long trips for any single engine non-pressurized piston airplane, and the frequency you need to go only increases the risk. Doing this VFR consistently is IMHO not very realistic, there are going to be times you’re going to have to wait out weather. Are the airlines not adequately meeting your travel needs; i.e., are you trying to get closer to your final destination by accessing airports the airlines don’t serve? Will this actually save enough time to justify doing it? Going from not flying at all for 15 years and no instrument rating to dispatching to frequent 1000nm business-critical trips in all kinds of likely weather conditions is an awful lot of mission to take on. If you “need” to get there on time for meetings or other business, that’s just going to increase the pressure on you and tempt you to disregard personal minimums. If, on the other hand, you just want to fly again, that can be done without taking it to such an extreme.
Your past experience counts a lot, and you know how to handle ownership, but it might realistically be a while until this mission actually becomes feasible, factoring in the equipment, training, proficiency, and preparation.
Just my two cents!