I do not intend to radically change the way I use bitcoin as I feel that I have the amount of security I desire. However, I do want to start using bip32 wallets instead and possible bip38 encription and possibly bip44 mnemonics.
There is no wallet that supports all of these 3. Note also that bip44 is a standard for structuring HD wallets and has nothing to do with mnemonics. That comes with bip39.
electrum 2.0 is a bip32 hd wallet that answers all your questions below but it is *not* bip39/44/38.
So the first question is: How do I manually input randomness to a bip32 seed generator tool?
You can do this with electrum 2.0 using the command line:
electrum --entropy= make_seed
electrum --entropy=3959389439878943984398743 make_seed
It'll output 12 words which is the seed in mnemonic form. Then run electrum and use the restore wallet option to create a wallet using that seed.
electrum -w /paht/to/new/walletfile
How easy would it be to monitor the balance of an HD wallet?
Electrum allows watch only wallets. To create a watch only wallet use the restore option and enter the master public key of the wallet you want to watch (There used to be a great guide but they've removed it from the site). On the "seeded wallet" (the one with the private keys i.e. not watch only) use wallet menu > master public key to get the mpk.
Do most wallets suport something like "HD watch only hierarchy"?
Yes that's what electrum watch only is. All the addresses in your wallet but none of the private keys so you can't spend from the watch only wallet.