Plenty of sea going boats are kept and used on rivers .
Better to have too much power than too little.
A 34ft sports cruiser is fairly big for a first boat . Assuming you propose to gain experience in the UK before crossing the channel.
We have slept 6 adults our similarly sized boat but...
Tecnoseal is the brand for Aluminium anodes I have been using for the outdrives, and this time also for the trim tabs
My bow thruster has a zinc anode. It is also available in Magnesium. I have not identified an Aluminium option.
The anodes for my boat were not on the shelf at the local chandlery and in any case the anodes they did have were priced quite a lot higher than online.
Ordering online was no problem and delivery was within a few days . I think for a few pounds extra I could have had next day delivery.
If...
I have been using aluminium anodes since 2015 on my present boat with anode changes every 2 years.
I used them also on my previous boat over something like 4 years
No known corrosion issues.
The boat is kept in fresh water with occasional salty water trips.
I left it too long and found lots of crud which took a lot of work to flush out. It's just easier to change the coolant every two years assuming it's Ethylene Glycol coolant.
I would say probably not
I am river based and do a lot of locks.
The boat can easily be pulled forward when going up and usually get pulled backwards and forwards
If only a single line is possible it should be middle cleat if there is one.
If you are going up never attach to the stern only
If you are going down then stern only may well be okay
I suggest moving the boat to get a line at the bow onto a riser them reverse , leaving plenty of slack to get a stern line on then adjust the ropes to put the boat somewhere between the...
From a high level structural perspective first thought is it looks like the tunnel leaves an uncomfortably small amount of GRP remaining .
Photographs looking from the inside may however add confidence .