Long Bike Rides, What to take?

You could take a Camelbak and carry more water with you... and possibly ditch the water bottles.

In Texas heat... 4 water/sports drink bottles would not be enough for a 100 mile ride.

Training ride for a distance event? or is it just a ride for leisure?

Everything you listed plus some $, a cell phone and a lens cloth to clean my sweat-splattered sunglasses.

My husband & I do long rides (70-100 miles) every Saturday & Sunday, weather permitting.  He carries a frame pump & 1 21oz. water bottle on his bike...the cellphone, extra tubes, & money in his seatbag...and a Clif Bar, and 1 or 2 Uncrustables in his jersey pockets. 

I carry...2 C02 cartridges & filler, tools, extra tubes, and Wetones packets in my seat bag...2 21oz. water bottles on my bike...chapstick, lens cloth, mini Clif bar, pack of Clif Shot bloks or some other "gummie" type of chew, and 2 Fig Newtons in my bento box...and some folded up papertowels (to wipe my sweaty face and/or sunglasses) in my jersey pocket. 

We always make at least 2 "planned" rest stops at gas stations along our route, to refill our bottles, eat our snacks that we brought along with us, and to use the bathroom. 

For a long ride like that I carry extra chamois lube and add some at every potty stop.

I can carry everything I need for a century in my jersey and I have no saddle bag or anything else.

Food/water:
I only carry two bottles on the frame and I stop at a store once or twice to refill them with Gatoraide. (I don't know how anybody rides with a Camelback). My lunch goes in a ziplock baggie taped up tightly with electrical tape. I keep the food that I'll be eating regularly loose in my back right pocket which are usually Nature Valley Sweet and salty bars with the ends of the wrappers cutoff with scissors. I can eat these easily without stopping.

For tools, ditch the pump for the smallest CO2 thing they make and carry two cartridges. I carry those, two tubes, a patch kit, two small levers, the three allen wrenches my bike needs, and a chain tool all packed tightly in a taped up ziplock that I take on every ride.

I carry some toilet paper, $, cell phone (always turned off) in another baggie untaped.

I roll up my arm warmers and warm gloves tightly inside my rain jacket in my middle pocket.

I have an MP3 player (and don't care what anybody thinks about it), in a small pocket on my tri shorts with the headphone wire under my jersey and hanging out of my neck hole.

Again, all of that fits in my jersey and I can barely even tell I'm carrying it.

I'm pretty sure a CO2 that's been used for one tire can put enough pressure into a second one to limp home. Although, I honestly can't remember ever doing it. I make sure that I determine exactly why I get a flat so I don't get repeat flats. My routes are also very clean and smooth so flats are rare for me. With a patch kit, I could also borrow a frame pump if a cyclist rode by with one.

For over 50 miles, I would bring 2x water bottles, a gel, $ & credit card, cellphone, a spare tube, tire levers, a CO2.

For 100miles, I would change the bottles to one water and one sports drink, plus an additional gel plus a snack bar. I I know I will be in a remote area, I might also bring an extra CO2 and a patch kit. Pretty much ever ride I do, I have a place to fill up the water bottles, so I never bring more than 2...

In a rear bike bag:  bike multi-tool (allen wrenches, screw driver, etc.), chain tool, spoke wrench, tire levers, patch kit, 2 CO2 cartridges and the attachment needed to use them, two spare tubes, two rubber bands, some emergency money.  All that just lives in that bag, rarely opened.

In my jersey in a ziploc bag:  cell phone, driver's license, ATM card, money to buy water refill in case I'm not passing by free refill.

In my jersey:  solid food (Cliff bars, dried fruit -- for me just those two things)

On my bike:  gel flask(s), two water bottles behind, concentrated sports drink on the down tube, aero bottle.

So yeah, I carry a lot of stuff, but I can go 80 miles with just one stop, over 100 with two.