tskk

That text isn’t even linked, but you can edit index-bone.php and add it.
wrap the <a> tag around :

<?php
	if( of_get_option('welcome_headline') ){
		echo esc_html( of_get_option('welcome_headline') );
	}else {
		_e('Welcome Headline Comes Here',  'alexandria');
	}
?>

i.e. line # 8 to line #14

Did you select static page and then some page in Dashboard->settings ->reading ?

For custom header setting, you need to go to Dashboard->Appearance->Header and add your own header image.

Fixed the scroll bar and submitted an update, it will be available soon.
This issue seems to be specific to chrome.

Will do. Will submit an update today or tomorrow.

in bizone settings tab or biztwo settings tab of theme options page depending on which layout you are using (bizone or biztwo)

Update is available now with a fix.

Fixed the issue with header showing up on blog page, update should be available soon.

custom header obeys the header settings, if you have turned header/slider off in pages, neither header or custom header will show.