I do not even know where to begin, and as a Hel pilot I have a pretty high resistance to tragedy.

Logout timer: this will increase the number of intentionally logged out supers (as counterintuitive as it is). An online supercapital can right now be held on the field by 3 things - dictor bubbles, hic point/bubble, anchored bubble. After this change, a drive-by shooting by an Ibis that gets off 2 shots (one for creating the timer, one for aggressing within that timer), means you have 30 minutes of infinitely-extendable aggression (remember the good old wreck-shooting).
An aggressed supercapital should stay in space for 15 minutes (like now), and after that for as long as it is bubbled or hic-pointed. I'm not going to do the math if a tech 2 velator could actually kill a supercapital within 23 hours, but if it can't, then downtime is the ONLY thing saving the supercap.
This in turn means a move back to a lot more aggression avoidance.

Supercarrier Dronetype change: Why not make Warrior IIs unfittable on battleships so the poor frigates do not get killed? I understand where the urge for this change comes from, but giving subcaps de facto immunity seems a bit much considered the only ships that can tackle them are destroyer/cruiser hulls.
There is little shame losing a super to a well coordinated trap, but the absolutely only business a single planless dictor solo engaging a super has is dying - not being granted possibly infinite amounts of near-invulnerable time to figure out what to do next. 300m3 dronebay for 20 lights and 20 meds (or rep drones) should be considered. Yes there are battleships dying to solo frigates all the time - but they had the option to fit something that helps and did not do it.

Supercarrier Fighterbay Size: given how hard fighters and fighter-bombers are to field-resupply (short of jumping a cargo-rorqual into an ongoing battle lol), how near impossible they are to rep (locktime, indeterminate flightpath), and how easily they die, I see a lot of useless supers 10 minutes into any engagement they are accidentally deployed into in our future. Will they receive more HP / better resistances? Or will there be a supercarrier retcon to capital bombers with 600m ISK bombs that jump in, deploy and (hope to somehow) jump out?

Titan dronebay: Yes, those 375m3 were the one gamebreaking attribute they had. All is well now. Please move along, nothing to see here.

Siege module: since it doesn't really change anything but the time needed for pos-ops, good.

Dreadnought dronebay: I love this change, since with this I do not have to wait another year or two for the "hey look, my sentry drone bumped your dread 500km offgrid" bug to be fixed. The single tackling rifter is going to be annoying though.

SC/Titan HP nerf: if 20% of a Hel were the same as 20% of an Aeon, I could subscribe to this change, but even if the Hel stays as it is, the -20% Aeon would still have twice the EHP. Consequently, this just reads to me as "ALL MINMATAR - BEND OVER NOW." Analog for the Ragnarok.

Not in the blog but needed changes:
Shield recharge: remove it from all capitals. Have capital shields behave like armor. Introduce +Capital Shield HP implant set (no drake/tengu love).

Hel bonus: either bring it inline with the other 3 supercarriers (offensive or defensive bonus), or fix its cap so it can actually use its bonus. +25% rep amount is ueless when you need twice the cap transfer amount of a nyx to not cap out (which gives you +100% rep and moar damage).

Dreadnought tracking: in theory, this would need a buff, but can be kept as is, since there will not be any big capital fights after this patch anyway.

Overall predictions for the proposed changes:
- dreads will still only be used to reinforce towers (not finish), and with the 5min timers they will be harder to catch doing so. they will continue to not be used against anything that can't be one-cycled, since they remain extremely vulnerable to supers and have to, or supers will lose their last remaining role. Having nothing to fend off tacklers on their own does not help either.

- carriers basically same as above. main use emergency logistics and triage-pos-boost, although they may see the odd use for structure grinding if no fight is to be expected. Since they can still launch drones that can effectively fight fighterbombers, they may get fielded in 200+ quantities so they generate enough remote rep to neutralize and finish off any supers on the field.

- supers will largely vanish from the battlefield again, since having a support fleet changed from smart play to required necessity. This implies the total loss of your supers, if you do not have dominance of the subcap fight - at which point you do not really need to deploy supers anymore. Since this is true for both sides, noone will dare to make the first move (depending on their knowledge of game theory).
Main use will be as a strategic deterrent against hostile dread/carrier deployments from within pos shields. Second most common usage will be parked on an inactive account. Highlight of the year might be a structure grind deployment if no hostile is logged in.