I. No re-join option after DC
Dynamic IP? Check.
Network outage? Check.
Wi-Fi? Check.
Server problems? Check.
Bugs? Check.
I understand Fractals were designed on purpose without waypoints (zerg-die-res-zerg loop), introducing a system of checkpoints instead. No problems with that. However, no kind of instanced content (dungeons) should punish players for disconnecting by removing their progress and disallowing them to enter back inside.
If you believe that forced disconnects would be abused, simply spawn re-joined players at the most recent checkpoint in defeated mode. Another thing you can do is limit re-joining to once every 90 seconds (or longer, if proven necessary). That way the DCed person doesn’t lose progress, and it’s team isn’t undermined by the whole situation.
Last remark: Fractals get increasingly difficult over time, requiring more group coordination and effort. For "raid" players doing fractals daily, guild/friend network and personal reputation are everything - disconnection issues at the higher difficulty stages will inevitably lead to lots of unnecessary drama, as well as prevent future growth of it’s community by encompassing players from different demographics.
II. No repair NPC inside a fractal
This one can go both ways, depending on how Instant Repair Canister is handled in the future.
If you disable this cash shop item in Fractals, you’ll send a clear message that a dungeon group needs to be "good enough" to complete 3 (sometimes 4, with "bonus level") fractals in a row without armour repair by not dying needlessly.
If you leave things as they are, starting from tier 3 onwards (tier 2 in PUGs) Instant Repair Canisters will become part of the "competitive ball", and all players refusing to use them when their armour breaks will be promptly kicked (once re-join is in place), if not outright blacklisted for future fractal runs on higher difficulty levels.
As it is now, a good mechanic making Fractals challenging and interesting can be entirely skipped with either direct cash transfer or forced "gold sink" through gold-gem conversion. Last time I checked, cash shop items were introduced to provide convenience, aesthetics and better time management chasing the fun stuff in the game.
Sadly, gold-gem conversion and cash shop items from daily achievements are no redeeming feature here, they merely serve to blur the line between acceptable and unacceptable practices, by gaining popular support. The following leads me to believe, that fractal dungeons were actually designed with Instant Repair Canisters in mind.
Last thing this community needs is gw2’s "endgame" labelled as "pay-to-win" over forums, blogs and other media channels. We don’t want that kind of publicity. For a reality check, try a full fractal run with armour unequipped, either on the upper difficulty levels of tier 1 or tier 2/3 directly - if not outright tedious, it will prove plain impossible.
more $$ for them.